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Calvert

Core Bond Fund

Semiannual Report

March 31, 2024

Commodity Futures Trading Commission Registration. The Commodity Futures Trading Commission (“CFTC”) has adopted regulations that subject registered investment companies and advisers to regulation by the CFTC if a fund invests more than a prescribed level of its assets in certain CFTC-regulated instruments (including futures, certain options and swap agreements) or markets itself as providing investment exposure to such instruments. The adviser has claimed an exclusion from the definition of “commodity pool operator” under the Commodity Exchange Act with respect to its management of the Fund and the other funds it manages. Accordingly, neither the Fund nor the adviser is subject to CFTC regulation.

Fund shares are not insured by the FDIC and are not deposits or other obligations of, or guaranteed by, any depository institution. Shares are subject to investment risks, including possible loss of principal invested.

This report must be preceded or accompanied by a current summary prospectus or prospectus. Before investing, investors should consider carefully the investment objective, risks, and charges and expenses of a mutual fund. This and other important information is contained in the summary prospectus and prospectus, which can be obtained from a financial intermediary. Prospective investors should read the prospectus carefully before investing. For further information, please call 1-800-368-2745.

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Semiannual Report March 31, 2024

Calvert

Core Bond Fund

Table of Contents
Performance	2
Fund Profile	3
Endnotes and Additional Disclosures	4
Fund Expenses	5
Financial Statements	6
Officers and Trustees	28
U.S. Customer Privacy Notice	29
Important Notices	32

Calvert

Core Bond Fund

March 31, 2024

Performance

Portfolio Manager(s) Vishal Khanduja, CFA and Brian S. Ellis, CFA, each of Calvert Research and Management

% Average Annual Total Returns1,2	Class Inception Date	Performance Inception Date	Six Months	One Year	Five Years	Ten Years
Class A at NAV	12/31/2004	12/31/2004	5.86%	1.85%	2.81%	3.60%
Class A with 3.25% Maximum Sales Charge	—	—	2.41	(1.46)	2.14	3.26
Class I at NAV	01/30/2015	12/31/2004	5.98	2.10	3.07	3.94
Class R6 at NAV	06/30/2023	12/31/2004	6.00	2.06	3.06	3.94
Bloomberg U.S. Aggregate Bond Index	—	—	5.99%	1.70%	0.36%	1.54%

    

% Total Annual Operating Expense Ratios3	Class A	Class I	Class R6
Gross	0.84%	0.59%	0.56%
Net	0.74	0.49	0.46

See Endnotes and Additional Disclosures in this report.

Past performance is no guarantee of future results. Returns are historical and are calculated by determining the percentage change in net asset value (NAV) or offering price (as applicable) with all distributions reinvested. Furthermore, returns do not reflect the deduction of taxes that shareholders may have to pay on Fund distributions or upon the redemption of Fund shares. Investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Performance for periods less than or equal to one year is cumulative. Performance is for the stated time period only; due to market volatility, current Fund performance may be lower or higher than the quoted return. For performance as of the most recent month-end, please refer to www.calvert.com.

2

Calvert

Core Bond Fund

March 31, 2024

Fund Profile

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3

Calvert

Core Bond Fund

March 31, 2024

Endnotes and Additional Disclosures

1	Bloomberg U.S. Aggregate Bond Index is an unmanaged index of domestic investment-grade bonds, including corporate, government and mortgage-backed securities. Unless otherwise stated, index returns do not reflect the effect of any applicable sales charges, commissions, expenses, taxes or leverage, as applicable. It is not possible to invest directly in an index.
2	Total Returns at NAV do not include applicable sales charges. If sales charges were deducted, the returns would be lower. Total Returns shown with maximum sales charge reflect the stated maximum sales charge. Unless otherwise stated, performance does not reflect the deduction of taxes on Fund distributions or redemptions of Fund shares. Performance prior to the inception date of a class may be linked to the performance of an older class of the Fund. This linked performance is adjusted for any applicable sales charge, but is not adjusted for class expense differences. If adjusted for such differences, the performance would be different. The performance of Class I is linked to Class A and the performance of Class R6 is linked to Class I. Performance presented in the Financial Highlights included in the financial statements is not linked. Effective February 1, 2021, the Fund revised its name, objective and principal investment strategies and adopted a policy of investing at least 80% of its net assets in investment grade, U.S. dollar-denominated debt securities. Calvert Research and Management became the investment adviser to the Fund on December 31, 2016. Performance reflected prior to such date is that of the Fund’s former investment adviser.
3	Source: Fund prospectus. Net expense ratios reflect a contractual expense reimbursement that continues through 2/1/25. The expense ratios for the current reporting period can be found in the Financial Highlights section of this report. Performance reflects expenses waived and/or reimbursed, if applicable. Without such waivers and/or reimbursements, performance would have been lower.

Fund profile subject to change due to active management.

4

Calvert

Core Bond Fund

March 31, 2024

Fund Expenses

Example

As a Fund shareholder, you incur two types of costs: (1) transaction costs, including sales charges (loads) on purchases; and (2) ongoing costs, including management fees; distribution and/or service fees; and other Fund expenses. This Example is intended to help you understand your ongoing costs (in dollars) of Fund investing and to compare these costs with the ongoing costs of investing in other mutual funds. The Example is based on an investment of $1,000 invested at the beginning of the period and held for the entire period (October 1, 2023 to March 31, 2024).

Actual Expenses

The first section of the table below provides information about actual account values and actual expenses. You may use the information in this section, together with the amount you invested, to estimate the expenses that you paid over the period. Simply divide your account value by $1,000 (for example, an $8,600 account value divided by $1,000 = 8.6), then multiply the result by the number in the first section under the heading entitled “Expenses Paid During Period” to estimate the expenses you paid on your account during this period.

Hypothetical Example for Comparison Purposes

The second section of the table below provides information about hypothetical account values and hypothetical expenses based on the actual Fund expense ratio and an assumed rate of return of 5% per year (before expenses), which is not the actual Fund return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing costs of investing in the Fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of the other funds.

Please note that the expenses shown in the table are meant to highlight your ongoing costs only and do not reflect any transactional costs, such as sales charges (loads). Therefore, the second section of the table is useful in comparing ongoing costs only, and will not help you determine the relative total costs of owning different funds. In addition, if these transactional costs were included, your costs would be higher.

	Beginning Account Value (10/1/23)	Ending Account Value (3/31/24)	Expenses Paid During Period* (10/1/23 – 3/31/24)	Annualized Expense Ratio
Actual
Class A	$1,000.00	$1,058.60	$3.86 **	0.75%
Class I	$1,000.00	$1,059.80	$2.57 **	0.50%
Class R6	$1,000.00	$1,060.00	$2.37 **	0.46%
Hypothetical
(5% return per year before expenses)
Class A	$1,000.00	$1,021.25	$3.79 **	0.75%
Class I	$1,000.00	$1,022.50	$2.53 **	0.50%
Class R6	$1,000.00	$1,022.70	$2.33 **	0.46%

    

*	Expenses are equal to the Fund’s annualized expense ratio for the indicated Class, multiplied by the average account value over the period, multiplied by 183/366 (to reflect the one-half year period). The Example assumes that the $1,000 was invested at the net asset value per share determined at the close of business on September 30, 2023.
**	Absent a waiver and/or reimbursement of expenses by affiliate(s), expenses would be higher.

5

Calvert

Core Bond Fund

March 31, 2024

Schedule of Investments (Unaudited)

Calvert

Core Bond Fund

March 31, 2024

Schedule of Investments (Unaudited) — continued

Calvert

Core Bond Fund

March 31, 2024

Schedule of Investments (Unaudited) — continued

Calvert

Core Bond Fund

March 31, 2024

Schedule of Investments (Unaudited) — continued

Calvert

Core Bond Fund

March 31, 2024

Schedule of Investments (Unaudited) — continued

Calvert

Core Bond Fund

March 31, 2024

Schedule of Investments (Unaudited) — continued

Calvert

Core Bond Fund

March 31, 2024

Schedule of Investments (Unaudited) — continued

Calvert

Core Bond Fund

March 31, 2024

Schedule of Investments (Unaudited) — continued

(15)	Represents investment of cash collateral received in connection with securities lending.

Futures Contracts

Description	Number of Contracts	Position	Expiration Date	Notional Amount	Value/ Unrealized Appreciation (Depreciation)
Interest Rate Futures
U.S. 2-Year Treasury Note	723	Long	6/28/24	$147,842,204	$ (52,707)
U.S. 5-Year Treasury Note	745	Long	6/28/24	79,726,641	142,993
U.S. 10-Year Treasury Note	87	Long	6/18/24	9,639,328	(108,170)
U.S. Long Treasury Bond	224	Long	6/18/24	26,978,000	334,411
U.S. Ultra 10-Year Treasury Note	(261)	Short	6/18/24	(29,913,047)	(217,065)
U.S. Ultra-Long Treasury Bond	(32)	Short	6/18/24	(4,128,000)	(61,172)
					$ 38,290

Restricted Securities

Description	Acquisition Date	Cost
Calvert Impact Capital, Inc., Community Investment Notes, 5.00%, 12/15/28	12/15/23	$2,000,000

    

Abbreviations:
SOFR	– Secured Overnight Financing Rate
STACR	– Structured Agency Credit Risk
TBA	– To Be Announced

13

See Notes to Financial Statements.

Calvert

Core Bond Fund

March 31, 2024

Statement of Assets and Liabilities (Unaudited)

	March 31, 2024
Assets
Investments in securities of unaffiliated issuers, at value (identified cost $1,034,067,626) - including $7,245,631 of securities on loan	$ 1,034,574,326
Investments in securities of affiliated issuers, at value (identified cost $22,163,509)	22,175,135
Cash	1,045,079
Deposits at broker for futures contracts	2,609,241
Receivable for investments sold	2,012,556
Receivable for capital shares sold	2,804,604
Interest receivable	8,438,740
Dividends and interest receivable - affiliated	105,534
Securities lending income receivable	750
Tax reclaims receivable	1,136
Receivable from affiliates	187,955
Trustees' deferred compensation plan	59,267
Prepaid expenses	3,781
Total assets	$1,074,018,104
Liabilities
Payable for variation margin on open futures contracts	$ 201,289
Payable for investments purchased	2,812,063
Payable for when-issued/forward commitment securities	162,594,358
Payable for capital shares redeemed	1,626,598
Distributions payable	3,076,841
Deposits for securities loaned	3,406,755
Payable to affiliates:
Investment advisory fee	223,033
Administrative fee	90,006
Distribution and service fees	15,879
Sub-transfer agency fee	3,273
Trustees' deferred compensation plan	59,267
Accrued expenses	110,744
Total liabilities	$ 174,220,106
Net Assets	$ 899,797,998
Sources of Net Assets
Paid-in capital	$ 921,551,259
Accumulated loss	(21,753,261)
Net Assets	$ 899,797,998
Class A Shares
Net Assets	$ 78,184,024
Shares Outstanding	4,978,795
Net Asset Value and Redemption Price Per Share (net assets ÷ shares of beneficial interest outstanding)	$ 15.70
Maximum Offering Price Per Share (100 ÷ 96.75 of net asset value per share)	$ 16.23
Class I Shares
Net Assets	$ 745,045,758
Shares Outstanding	47,378,814
Net Asset Value, Offering Price and Redemption Price Per Share (net assets ÷ shares of beneficial interest outstanding)	$ 15.73

14

See Notes to Financial Statements.

Calvert

Core Bond Fund

March 31, 2024

Statement of Assets and Liabilities (Unaudited) — continued

	March 31, 2024
Class R6 Shares
Net Assets	$ 76,568,216
Shares Outstanding	4,870,688
Net Asset Value, Offering Price and Redemption Price Per Share (net assets ÷ shares of beneficial interest outstanding)	$ 15.72

    

On sales of $100,000 or more, the offering price of Class A shares is reduced.

15

See Notes to Financial Statements.

Calvert

Core Bond Fund

March 31, 2024

Statement of Operations (Unaudited)

	Six Months Ended
	March 31, 2024
Investment Income
Dividend income - affiliated issuers	$ 424,137
Interest income	19,625,156
Interest income - affiliated issuers	73,336
Securities lending income, net	6,947
Other income	1,063
Total investment income	$20,130,639
Expenses
Investment advisory fee	$ 1,160,848
Administrative fee	464,339
Distribution and service fees:
Class A	83,717
Trustees' fees and expenses	20,543
Custodian fees	16,248
Transfer agency fees and expenses	269,855
Accounting fees	88,549
Professional fees	29,557
Registration fees	78,618
Reports to shareholders	30,708
Interest expense and fees	42,409
Miscellaneous	32,519
Total expenses	$ 2,317,910
Waiver and/or reimbursement of expenses by affiliates	$ (310,382)
Net expenses	$ 2,007,528
Net investment income	$18,123,111
Realized and Unrealized Gain (Loss)
Net realized gain (loss):
Investment securities	$ (3,147,341)
Futures contracts	(185,282)
Net realized loss	$ (3,332,623)
Change in unrealized appreciation (depreciation):
Investment securities	$ 25,603,233
Investment securities - affiliated issuers	6,711
Futures contracts	1,338,003
Net change in unrealized appreciation (depreciation)	$26,947,947
Net realized and unrealized gain	$23,615,324
Net increase in net assets from operations	$41,738,435

16

See Notes to Financial Statements.

Calvert

Core Bond Fund

March 31, 2024

Statements of Changes in Net Assets

	Six  Months Ended March 31, 2024 (Unaudited)	Year Ended September 30, 2023
Increase (Decrease) in Net Assets
From operations:
Net investment income	$ 18,123,111	$ 15,097,666
Net realized loss	(3,332,623)	(16,633,787)
Net change in unrealized appreciation (depreciation)	26,947,947	(8,719,280)
Net increase (decrease) in net assets from operations	$ 41,738,435	$ (10,255,401)
Distributions to shareholders:
Class A	$ (1,475,689)	$ (1,735,011)
Class I	(15,999,351)	(13,214,469)
Class R6	(415,466)	(553) (1)
Total distributions to shareholders	$ (17,890,506)	$ (14,950,033)
Capital share transactions:
Class A	$ 16,731,804	$ 17,940,387
Class I	137,130,836	477,347,275
Class R6	76,099,277	50,553 (1)
Net increase in net assets from capital share transactions	$229,961,917	$495,338,215
Net increase in net assets	$253,809,846	$470,132,781
Net Assets
At beginning of period	$ 645,988,152	$ 175,855,371
At end of period	$899,797,998	$645,988,152

    

(1)	For the period from the commencement of operations, June 30, 2023, to September 30, 2023.

17

See Notes to Financial Statements.

Calvert

Core Bond Fund

March 31, 2024

Financial Highlights

	Class A
	Six Months Ended March 31, 2024 (Unaudited)	Year Ended September 30,
		2023	2022	2021	2020	2019
Net asset value — Beginning of period	$ 15.16	$ 15.59	$ 19.49	$ 19.97	$ 18.45	$ 16.07
Income (Loss) From Operations
Net investment income(1)	$ 0.35	$ 0.57	$ 0.29	$ 0.30	$ 0.51	$ 0.56
Net realized and unrealized gain (loss)	0.53	(0.44)	(3.03)	0.06	1.53	2.39
Total income (loss) from operations	$ 0.88	$ 0.13	$ (2.74)	$ 0.36	$ 2.04	$ 2.95
Less Distributions
From net investment income	$ (0.34)	$ (0.56)	$ (0.30)	$ (0.30)	$ (0.52)	$ (0.57)
From net realized gain	—	—	(0.86)	(0.54)	—	—
Total distributions	$ (0.34)	$ (0.56)	$ (1.16)	$ (0.84)	$ (0.52)	$ (0.57)
Net asset value — End of period	$ 15.70	$ 15.16	$ 15.59	$ 19.49	$ 19.97	$ 18.45
Total Return(2)	5.86% (3)	0.76%	(14.78)%	1.79%	11.21%	18.81%
Ratios/Supplemental Data
Net assets, end of period (000’s omitted)	$78,184	$59,235	$43,106	$50,647	$52,965	$51,709
Ratios (as a percentage of average daily net assets):(4)
Total expenses	0.83% (5)(6)	0.84%	0.91%	0.97%	1.05%	1.14%
Net expenses	0.75% (5)(6)(7)	0.74% (7)	0.74% (7)	0.80%	0.92%	0.92%
Net investment income	4.46% (5)	3.64%	1.65%	1.52%	2.70%	3.33%
Portfolio Turnover	180% (3)(8)	226% (8)	175% (8)	195% (8)	52%	43%

    

(1)	Computed using average shares outstanding.
(2)	Returns are historical and are calculated by determining the percentage change in net asset value with all distributions reinvested and do not reflect the effect of sales charges, if any.
(3)	Not annualized.
(4)	Total expenses do not reflect amounts reimbursed and/or waived by the adviser and certain of its affiliates, if applicable. Net expenses are net of all reductions and represent the net expenses paid by the Fund.
(5)	Annualized.
(6)	Includes interest expense of 0.01% of average daily net assets for the six months ended March 31, 2024.
(7)	Includes a reduction by the investment adviser of a portion of its advisory fee due to the Fund’s investment in the Liquidity Fund (equal to less than 0.005% of average daily net assets for the six months ended March 31, 2024 and the years ended September 30, 2023 and 2022).
(8)	Includes the effect of To Be Announced (TBA) transactions.

18

See Notes to Financial Statements.

Calvert

Core Bond Fund

March 31, 2024

Financial Highlights — continued

	Class I
	Six Months Ended March 31, 2024 (Unaudited)	Year Ended September 30,
		2023	2022	2021	2020	2019
Net asset value — Beginning of period	$ 15.18	$ 15.61	$ 19.51	$ 20.00	$ 18.47	$ 16.08
Income (Loss) From Operations
Net investment income(1)	$ 0.37	$ 0.63	$ 0.35	$ 0.36	$ 0.56	$ 0.60
Net realized and unrealized gain (loss)	0.54	(0.46)	(3.04)	0.04	1.54	2.41
Total income (loss) from operations	$ 0.91	$ 0.17	$ (2.69)	$ 0.40	$ 2.10	$ 3.01
Less Distributions
From net investment income	$ (0.36)	$ (0.60)	$ (0.35)	$ (0.35)	$ (0.57)	$ (0.62)
From net realized gain	—	—	(0.86)	(0.54)	—	—
Total distributions	$ (0.36)	$ (0.60)	$ (1.21)	$ (0.89)	$ (0.57)	$ (0.62)
Net asset value — End of period	$ 15.73	$ 15.18	$ 15.61	$ 19.51	$ 20.00	$ 18.47
Total Return(2)	5.98% (3)	1.09%	(14.55)%	1.99%	11.53%	19.14%
Ratios/Supplemental Data
Net assets, end of period (000’s omitted)	$745,046	$586,705	$132,749	$42,399	$54,009	$33,302
Ratios (as a percentage of average daily net assets):(4)
Total expenses	0.58% (5)(6)	0.59%	0.66%	0.72%	0.80%	0.87%
Net expenses	0.50% (5)(6)(7)	0.49% (7)	0.49% (7)	0.55%	0.67%	0.63%
Net investment income	4.69% (5)	4.02%	2.07%	1.81%	2.93%	3.53%
Portfolio Turnover	180% (3)(8)	226% (8)	175% (8)	195% (8)	52%	43%

    

(1)	Computed using average shares outstanding.
(2)	Returns are historical and are calculated by determining the percentage change in net asset value with all distributions reinvested and do not reflect the effect of sales charges, if any.
(3)	Not annualized.
(4)	Total expenses do not reflect amounts reimbursed and/or waived by the adviser and certain of its affiliates, if applicable. Net expenses are net of all reductions and represent the net expenses paid by the Fund.
(5)	Annualized.
(6)	Includes interest expense of 0.01% of average daily net assets for the six months ended March 31, 2024.
(7)	Includes a reduction by the investment adviser of a portion of its advisory fee due to the Fund’s investment in the Liquidity Fund (equal to less than 0.005% of average daily net assets for the six months ended March 31, 2024 and the years ended September 30, 2023 and 2022).
(8)	Includes the effect of To Be Announced (TBA) transactions.

19

See Notes to Financial Statements.

Calvert

Core Bond Fund

March 31, 2024

Financial Highlights — continued

	Class R6
	Six Months Ended March 31, 2024 (Unaudited)	Period Ended September 30, 2023(1)
Net asset value — Beginning of period	$ 15.18	$ 15.79
Income (Loss) From Operations
Net investment income(2)	$ 0.37	$ 0.17
Net realized and unrealized gain (loss)	0.53	(0.61)
Total income (loss) from operations	$ 0.90	$ (0.44)
Less Distributions
From net investment income	$ (0.36)	$ (0.17)
Total distributions	$ (0.36)	$ (0.17)
Net asset value — End of period	$ 15.72	$15.18
Total Return(3)	6.00% (4)	(2.78)% (4)
Ratios/Supplemental Data
Net assets, end of period (000’s omitted)	$76,568	$ 49
Ratios (as a percentage of average daily net assets):(5)
Total expenses	0.57% (6)	0.56% (6)
Net expenses	0.46% (6)(7)	0.46% (6)(7)
Net investment income	4.68% (6)	4.41% (6)
Portfolio Turnover	180% (4)(8)	226% (8)(9)

    

(1)	For the period from the commencement of operations, June 30, 2023, to September 30, 2023.
(2)	Computed using average shares outstanding.
(3)	Returns are historical and are calculated by determining the percentage change in net asset value with all distributions reinvested and do not reflect the effect of sales charges, if any.
(4)	Not annualized.
(5)	Total expenses do not reflect amounts reimbursed and/or waived by the adviser and certain of its affiliates, if applicable. Net expenses are net of all reductions and represent the net expenses paid by the Fund.
(6)	Annualized.
(7)	Includes a reduction by the investment adviser of a portion of its advisory fee due to the Fund’s investment in the Liquidity Fund (equal to less than 0.005% of average daily net assets for the six months ended March 31, 2024 and the period ended September 30, 2023).
(8)	Includes the effect of To Be Announced (TBA) transactions.
(9)	For the year ended September 30, 2023.

20

See Notes to Financial Statements.

Calvert

Core Bond Fund

March 31, 2024

Notes to Financial Statements (Unaudited)

1  Significant Accounting Policies

Calvert Core Bond Fund (the Fund) is a diversified series of The Calvert Fund (the Trust). The Trust is a Massachusetts business trust registered under the Investment Company Act of 1940, as amended (the 1940 Act), as an open-end management investment company. The investment objective of the Fund is to seek total return with an emphasis on income. The Fund invests primarily in investment grade, U.S. dollar denominated securities.

The Fund offers three classes of shares. Class A shares are generally sold subject to a sales charge imposed at time of purchase. A contingent deferred sales charge of 0.75% may apply to certain redemptions of Class A shares for accounts for which no sales charge was paid, if redeemed within 12 months of purchase. Class I and Class R6 shares are sold at net asset value, are not subject to a sales charge and are sold only to certain eligible investors. Each class represents a pro rata interest in the Fund, but votes separately on class-specific matters and is subject to different expenses.

The Fund applies the accounting and reporting guidance in the Financial Accounting Standards Board (FASB) Accounting Standards Codification Topic 946, Financial Services – Investment Companies (ASC 946). Subsequent events, if any, through the date that the financial statements were issued have been evaluated in the preparation of the financial statements.

A  Investment Valuation— Net asset value per share is determined every business day as of the close of the regular session of the New York Stock Exchange (generally 4:00 p.m. Eastern time). The Fund uses independent pricing services approved by the Board of Trustees (the Board) to value its investments wherever possible. Investments for which market quotations are not available or deemed not reliable are fair valued in good faith by the Board’s valuation designee.

U.S. generally accepted accounting principles (U.S. GAAP) establishes a disclosure hierarchy that categorizes the inputs to valuation techniques used to value assets and liabilities at measurement date. These inputs are summarized in the three broad levels listed below:

Level 1 - quoted prices in active markets for identical securities

Level 2 - other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk, etc.)

Level 3 - significant unobservable inputs (including the Fund’s own assumptions in determining the fair value of investments)

The inputs or methodologies used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

Valuation techniques used to value the Fund’s investments by major category are as follows:

Debt Securities. Debt securities are generally valued based on valuations provided by third party pricing services, as derived from such services’ pricing models. Inputs to the models may include, but are not limited to, reported trades, executable bid and ask prices, broker/dealer quotations, prices or yields of securities with similar characteristics, interest rates, anticipated prepayments, benchmark curves or information pertaining to the issuer, as well as industry and economic events. Accordingly, debt securities are generally categorized as Level 2 in the hierarchy. Short-term debt securities with a remaining maturity at time of purchase of more than sixty days are valued based on valuations provided by a third party pricing service. Such securities are generally categorized as Level 2 in the hierarchy. Short-term debt securities of sufficient credit quality purchased with remaining maturities of sixty days or less for which a valuation from a third party pricing service is not readily available may be valued at amortized cost, which approximates fair value, and are categorized as Level 2 in the hierarchy.

Other Securities. Investments in management investment companies (including money market funds) that do not trade on an exchange are valued at the net asset value as of the close of each business day and are categorized as Level 1 in the hierarchy.

Derivatives. Futures contracts are valued at unrealized appreciation (depreciation) based on the settlement price established each day by the board of trade or exchange on which they are traded and are categorized as Level 1 in the hierarchy. U.S. exchange-traded options are valued at the mean between the bid and ask prices at valuation time as reported by the Options Price Reporting Authority and are categorized as Level 1 in the hierarchy.

Fair Valuation. In connection with Rule 2a-5 of the 1940 Act, the Board has designated the Fund’s investment adviser as its valuation designee. Investments for which valuations or market quotations are not readily available or are deemed unreliable are valued by the investment adviser, as valuation designee, at fair value using methods that most fairly reflect the security’s “fair value”, which is the amount that the Fund might reasonably expect to receive for the security upon its current sale in the ordinary course. Each such determination is based on a consideration of relevant factors, which are likely to vary from one pricing context to another. These factors may include, but are not limited to, the type of security, the existence of any contractual restrictions on the security’s disposition, the price and extent of public trading in similar securities of the issuer or of comparable companies or entities, quotations or relevant information obtained from broker/dealers or other market participants, information obtained from the issuer, analysts, and/or the appropriate stock exchange (for exchange-traded securities), an analysis of the company’s or entity’s financial statements, and an evaluation of the forces that influence the issuer and the market(s) in which the security is purchased and sold.

The values assigned to fair value investments are based on available information and do not necessarily represent amounts that might ultimately be realized. Further, due to the inherent uncertainty of valuations of such investments, the fair values may differ significantly from the values that would have been used had an active market existed, and the differences could be material.

21

Calvert

Core Bond Fund

March 31, 2024

Notes to Financial Statements (Unaudited) — continued

The following table summarizes the market value of the Fund's holdings as of March 31, 2024, based on the inputs used to value them:

Asset Description	Level 1	Level 2	Level 3	Total
Asset-Backed Securities	$  —	$ 127,697,885	$  —	$ 127,697,885
Collateralized Mortgage Obligations	—	17,839,992	—	17,839,992
Commercial Mortgage-Backed Securities	—	100,025,229	—	100,025,229
Corporate Bonds	—	297,820,833	—	297,820,833
High Social Impact Investments	—	1,972,580	—	1,972,580
Sovereign Government Bonds	—	7,332,587	—	7,332,587
Taxable Municipal Obligations	—	1,798,416	—	1,798,416
U.S. Government Agencies and Instrumentalities	—	332,452	—	332,452
U.S. Government Agency Mortgage-Backed Securities	—	195,288,995	—	195,288,995
U.S. Treasury Obligations	—	259,265,025	—	259,265,025
Short-Term Investments:
Affiliated Fund	19,131,958	—	—	19,131,958
Securities Lending Collateral	3,406,755	—	—	3,406,755
U.S. Treasury Obligations	—	24,836,754	—	24,836,754
Total Investments	$22,538,713	$1,034,210,748	$ —	$1,056,749,461
Futures Contracts	$ 477,404	$  —	$  —	$ 477,404
Total	$23,016,117	$1,034,210,748	$ —	$1,057,226,865
Liability Description
Futures Contracts	$ (439,114)	$  —	$  —	$ (439,114)
Total	$ (439,114)	$  —	$ —	$ (439,114)

B  Investment Transactions and Income— Investment transactions for financial statement purposes are accounted for on trade date. Realized gains and losses are recorded on an identified cost basis and may include proceeds from litigation. Dividend income is recorded on the ex-dividend date for dividends received in cash and/or securities. Non-cash dividends are recorded at the fair value of the securities received. Distributions received that represent a return of capital are recorded as a reduction of cost of investments. Distributions received that represent a capital gain are recorded as a realized gain. Interest income, which includes amortization of premium and accretion of discount on debt securities, is accrued as earned.

C  Share Class Accounting— Realized and unrealized gains and losses are allocated daily to each class of shares based upon the relative net assets of each class to the total net assets of the Fund. Net investment income, other than class-specific expenses, is allocated daily to each class of shares based upon the ratio of the value of each class's paid shares to the total value of all paid shares. Expenses arising in connection with a specific class are charged directly to that class. Sub-accounting, recordkeeping and similar administrative fees payable to financial intermediaries, which are a component of transfer agency fees and expenses on the Statement of Operations, are not allocated to Class R6 shares. 

D  Futures Contracts— The Fund may enter into futures contracts to buy or sell a financial instrument for a set price at a future date. Initial margin deposits of either cash or securities as required by the broker are made upon entering into the contract. While the contract is open, daily variation margin payments are made to or received from the broker reflecting the daily change in market value of the contract and are recorded for financial reporting purposes as unrealized gains or losses by the Fund. When a futures contract is closed, a realized gain or loss is recorded equal to the difference between the opening and closing value of the contract. The risks associated with entering into futures contracts may include the possible illiquidity of the secondary market which would limit the Fund’s ability to close out a futures contract prior to the settlement date, an imperfect correlation between the value of the contracts and the underlying financial instruments, or that the counterparty will fail to perform its obligations under the contracts’ terms. Futures contracts are designed by boards of trade, which are designated “contracts markets” by the Commodities Futures Trading Commission. Futures contracts trade on the contracts markets in a manner that is similar to the way a stock trades on a stock exchange, and the boards of trade, through their clearing corporations, guarantee the futures contracts against default. As a result, there is minimal counterparty credit risk to the Fund.

E  Options Contracts— Upon the purchase of a call or put option, the premium paid by the Fund is included in the Statement of Assets and Liabilities as an investment. The amount of the investment is subsequently marked-to-market to reflect the current market value of the option purchased, in accordance with the Fund's policies on investment valuations discussed above. Premiums paid for purchasing options that expire are treated as realized losses. Premiums paid for purchasing options that are exercised or closed are added to the amounts paid or offset against the proceeds on the underlying

22

Calvert

Core Bond Fund

March 31, 2024

Notes to Financial Statements (Unaudited) — continued

investment transaction to determine the realized gain or loss. As the purchaser of an index option, the Fund has the right to receive a cash payment equal to any depreciation in the value of the index below the exercise price of the option (in the case of a put) or equal to any appreciation in the value of the index over the exercise price of the option (in the case of a call) as of the valuation date of the option. The risk associated with purchasing options is limited to the premium originally paid. Purchased options traded over-the-counter involve risk that the issuer or counterparty will fail to perform its contractual obligations.

F  Restricted Securities— The Fund may invest in securities that are subject to legal or contractual restrictions on resale. Generally, these securities may only be sold publicly upon registration under the Securities Act of 1933 or in transactions exempt from such registration. Information regarding restricted securities (excluding Rule 144A securities) is included at the end of the Schedule of Investments.

G  Distributions to Shareholders— Distributions to shareholders are recorded by the Fund on ex-dividend date. The Fund declares income distributions daily to shareholders of record at the time of declaration and generally pays them monthly. The Fund makes distributions of net realized capital gains, if any, at least annually. Distributions are declared separately for each class of shares. Distributions are determined in accordance with income tax regulations, which may differ from U.S. GAAP; accordingly, periodic reclassifications are made within the Fund’s capital accounts to reflect income and gains available for distribution under income tax regulations.

H  Estimates— The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of increases and decreases in net assets from operations during the reporting period. Actual results could differ from those estimates.

I   Indemnifications— Under the Trust’s organizational document, its officers and Trustees may be indemnified against certain liabilities and expenses arising out of the performance of their duties to the Fund. Under Massachusetts law, if certain conditions prevail, shareholders of a Massachusetts business trust (such as the Trust) could be deemed to have personal liability for the obligations of the Trust. However, the Trust’s Declaration of Trust contains an express disclaimer of liability on the part of Fund shareholders and provides that the Trust shall assume, upon request by the shareholder, the defense on behalf of any Fund shareholders or former shareholders. Additionally, in the normal course of business, the Fund enters into agreements with service providers that may contain indemnification clauses. The Fund’s maximum exposure under these arrangements is unknown as this would involve future claims that may be made against the Fund that have not yet occurred.

J  Federal Income Taxes— No provision for federal income or excise tax is required since the Fund intends to continue to qualify as a regulated investment company under the Internal Revenue Code and to distribute substantially all of its taxable earnings.

Management has analyzed the Fund's tax positions taken for all open federal income tax years and has concluded that no provision for federal income tax is required in the Fund's financial statements. A Fund's federal tax return is subject to examination by the Internal Revenue Service for a period of three years from the date of filing.

K  When-Issued Securities and Delayed Delivery Transactions— The Fund may purchase securities on a delayed delivery, when-issued or forward commitment basis, including TBA (To Be Announced) securities. Payment and delivery may take place after the customary settlement period for that security. At the time the transaction is negotiated, the price of the security that will be delivered is fixed. Securities purchased on a delayed delivery, when-issued or forward commitment basis are marked-to-market daily and begin earning interest on settlement date. Such security purchases are subject to the risk that when delivered they will be worth less than the agreed upon payment price. Losses may also arise if the counterparty does not perform under the contract. A forward purchase commitment may be closed by entering into an offsetting commitment. If an offsetting commitment is entered into, the Fund will realize a gain or loss on investments based on the price established when the Fund entered into the commitment.

L  Interim Financial Statements— The interim financial statements relating to March 31, 2024 and for the six months then ended have not been audited by an independent registered public accounting firm, but in the opinion of the Fund's management, reflect all adjustments, consisting only of normal recurring adjustments, necessary for the fair presentation of the financial statements.

2  Related Party Transactions

The investment advisory fee is earned by Calvert Research and Management (CRM), an indirect, wholly-owned subsidiary of Morgan Stanley, as compensation for investment advisory services rendered to the Fund. The investment advisory fee is computed at the annual rate of 0.30% of the Fund’s average daily net assets and is payable monthly. For the six months ended March 31, 2024, the investment advisory fee amounted to $1,160,848. 

The Fund may invest in a money market fund, the Institutional Class of the Morgan Stanley Institutional Liquidity Funds - Government Portfolio (the “Liquidity Fund”), an open-end management investment company managed by Morgan Stanley Investment Management Inc., a wholly-owned subsidiary of Morgan Stanley. The investment advisory fee paid by the Fund is reduced by an amount equal to its pro rata share of the advisory and administration fees paid by the Fund due to its investment in the Liquidity Fund. For the six months ended March 31, 2024, the investment advisory fee paid was reduced by $11,970 relating to the Fund’s investment in the Liquidity Fund.

23

Calvert

Core Bond Fund

March 31, 2024

Notes to Financial Statements (Unaudited) — continued

CRM has agreed to reimburse the Fund’s operating expenses to the extent that total annual operating expenses (relating to ordinary operating expenses only and excluding expenses such as brokerage commissions, acquired fund fees and expenses of unaffiliated funds, borrowing costs, taxes or litigation expenses) exceed 0.74%, 0.49% and 0.46% for Class A, Class I and Class R6, respectively, of such class's average daily net assets. The expense reimbursement agreement with CRM may be changed or terminated after February 1, 2025. For the six months ended March 31, 2024, CRM waived or reimbursed expenses of $298,412.

The administrative fee is earned by CRM as compensation for administrative services rendered to the Fund. The fee is computed at an annual rate of 0.12% of the Fund’s average daily net assets attributable to Class A, Class I and Class R6 and is payable monthly. For the six months ended March 31, 2024, CRM was paid administrative fees of $464,339.

The Fund has in effect a distribution plan for Class A shares (Class A Plan) pursuant to Rule 12b-1 under the 1940 Act. Pursuant to the Class A Plan, the Fund pays Eaton Vance Distributors, Inc. (EVD), an affiliate of CRM and the Fund’s principal underwriter, a distribution and service fee of 0.25% per annum of its average daily net assets attributable to Class A shares for distribution services and facilities provided to the Fund by EVD, as well as for personal services and/or the maintenance of shareholder accounts. Distribution and service fees paid or accrued for the six months ended March 31, 2024 amounted to $83,717 for Class A shares.

The Fund was informed that EVD received $10,818 as its portion of the sales charge on sales of Class A shares and no contingent deferred sales charges paid by Fund shareholders for the six months ended March 31, 2024.

Eaton Vance Management (EVM), an affiliate of CRM, provides sub-transfer agency and related services to the Fund pursuant to a Sub-Transfer Agency Support Services Agreement. For the six months ended March 31, 2024, sub-transfer agency fees and expenses incurred to EVM amounted to $7,108 and are included in transfer agency fees and expenses on the Statement of Operations.

Each Trustee of the Fund who is not an employee of CRM or its affiliates receives an annual fee of $225,000 ($214,000 prior to January 1, 2024), an annual Committee fee ranging from $8,500 to $16,500 depending on the Committee, and may receive a fee of $10,000 for special meetings. The Board chair receives an additional $40,000 annual fee, Committee chairs receive an additional $15,000 annual fee and the special equities liaison receives an additional $2,500 annual fee. Eligible Trustees may participate in a Deferred Compensation Plan (the Plan). Amounts deferred under the Plan are treated as though equal dollar amounts had been invested in shares of the Fund or other Calvert funds selected by the Trustees. The Fund purchases shares of the funds selected equal to the dollar amounts deferred under the Plan, resulting in an asset equal to the deferred compensation liability. Obligations of the Plan are paid solely from the Fund's assets. Trustees’ fees are allocated to each of the Calvert funds served. Salaries and fees of officers and Trustees of the Fund who are employees of CRM or its affiliates are paid by CRM.

3  Investment Activity

During the six months ended March 31, 2024, the cost of purchases and proceeds from sales of investments, other than U.S. government and agency securities and short-term securities and including paydowns, were $410,674,613 and $201,934,186, respectively. Purchases and sales of U.S. government and agency securities, including paydowns and TBA transactions, were $1,430,432,893 and $1,343,417,482, respectively.

4  Distributions to Shareholders and Income Tax Information

At September 30, 2023, the Fund, for federal income tax purposes, had deferred capital losses of $20,124,089 which would reduce the Fund's taxable income arising from future net realized gains on investment transactions, if any, to the extent permitted by the Internal Revenue Code, and thus would reduce the amount of distributions to shareholders, which would otherwise be necessary to relieve the Fund of any liability for federal income or excise tax. The deferred capital losses are treated as arising on the first day of the Fund's next taxable year, can be carried forward for an unlimited period, and retain the same short-term or long-term character as when originally deferred. Of the deferred capital losses at September 30, 2023, $12,837,181 are short-term and $7,286,908 are long-term.

The cost and unrealized appreciation (depreciation) of investments, including open derivative contracts, of the Fund at March 31, 2024, as determined on a federal income tax basis, were as follows:

Aggregate cost	$1,056,601,812
Gross unrealized appreciation	$ 7,971,977
Gross unrealized depreciation	(7,786,038)
Net unrealized appreciation	$ 185,939

24

Calvert

Core Bond Fund

March 31, 2024

Notes to Financial Statements (Unaudited) — continued

5  Financial Instruments

A summary of futures contracts outstanding at March 31, 2024 is included in the Schedule of Investments.

During the six months ended March 31, 2024, the Fund used futures contracts and options on futures contracts to hedge interest rate risk and to manage duration.

At March 31, 2024, the fair value of open derivative instruments (not considered to be hedging instruments for accounting disclosure purposes) and whose primary underlying risk exposure is interest rate risk was as follows:

Derivative	Statement of Assets and Liabilities Caption		Assets	Liabilities
Futures contracts	Accumulated loss		$477,404 (1)	$(439,114) (1)

    

(1)	Only the current day's variation margin is reported within the Statement of Assets and Liabilities as Receivable or Payable for variation margin on open futures contracts, as applicable.

The effect of derivative instruments (not considered to be hedging instruments for accounting disclosure purposes) on the Statement of Operations by risk exposure for the six months ended March 31, 2024 was as follows:

Statement of Operations Caption	Interest rate
Net realized gain (loss):
Investment securities(1)	$ (100,207)
Futures contracts	(185,282)
Total	$ (285,489)
Change in unrealized appreciation (depreciation):
Investment securities(1)	$ (69,094)
Futures contracts	1,338,003
Total	$1,268,909

    

(1)	Relates to purchased options.

The average notional cost of futures contracts outstanding during the six months ended March 31, 2024, which are indicative of the volume of these derivative types, were approximately as follows:

Futures Contracts — Long	Futures Contracts — Short
$203,886,000	$12,637,000

The average number of purchased options contracts outstanding during the six months ended March 31, 2024, which is indicative of the volume of this derivative type, was 74 contracts.

6  Securities Lending

To generate additional income, the Fund may lend its securities pursuant to a securities lending agency agreement with State Street Bank and Trust Company (SSBT), the securities lending agent. Security loans are subject to termination by the Fund at any time and, therefore, are not considered illiquid investments. The Fund requires that the loan be continuously collateralized by either cash or securities in an amount at least equal to the market value of the securities on loan. The market value of securities loaned is determined daily and any additional required collateral is delivered to the Fund on the next business day. Cash collateral is generally invested in a money market fund registered under the 1940 Act that is managed by an affiliate of SSBT. Any gain or loss in the market price of the loaned securities that might occur and any interest earned or dividends declared during the term of the loan would accrue to the account of the Fund. Income earned on the investment of collateral, net of broker rebates and other expenses incurred by the securities lending agent, is split between the Fund and the securities lending agent based on agreed upon contractual terms. Non-cash collateral, if any, is held by the lending agent on behalf of the Fund and cannot be sold or re-pledged by the Fund; accordingly, such collateral is not reflected in the Statement of Assets and Liabilities.

25

Calvert

Core Bond Fund

March 31, 2024

Notes to Financial Statements (Unaudited) — continued

The risks associated with lending portfolio securities include, but are not limited to, possible delays in receiving additional collateral or in the recovery of the loaned securities, possible loss of rights to the collateral should the borrower fail financially, as well as risk of loss in the value of the collateral or the value of the investments made with the collateral. The securities lending agent shall indemnify the Fund in the case of default of any securities borrower.

At March 31, 2024, the total value of securities on loan, including accrued interest, was $7,324,514 and the total value of collateral received was $7,471,056, comprised of cash of $3,406,755 and U.S. government and/or agencies securities of $4,064,301.

The following table provides a breakdown of securities lending transactions accounted for as secured borrowings, the obligations by class of collateral pledged, and the remaining contractual maturity of those transactions as of March 31, 2024.

	Remaining Contractual Maturity of the Transactions
	Overnight and Continuous	<30 days	30 to 90 days	>90 days	Total
Corporate Bonds	$ 1,795,635	$  —	$  —	$  —	$ 1,795,635
U.S. Treasury Obligations	1,611,120	—	—	—	1,611,120
Total	$3,406,755	$ —	$ —	$ —	$3,406,755

The carrying amount of the liability for deposits for securities loaned at March 31, 2024 approximated its fair value. If measured at fair value, such liability would have been considered as Level 2 in the fair value hierarchy (see Note 1A) at March 31, 2024.

7  Line of Credit

The Fund participates with other portfolios and funds managed by EVM and its affiliates, including CRM, in a $650 million unsecured revolving line of credit agreement with a group of banks, which is in effect through October 22, 2024. In connection with the renewal of the agreement on October 24, 2023, the borrowing limit was decreased from $725 million. Borrowings are made by the Fund solely for temporary purposes related to redemptions and other short-term cash needs. Interest is charged to the Fund based on its borrowings at an amount above either the Secured Overnight Financing Rate (SOFR) or Federal Funds rate. In addition, a fee computed at an annual rate of 0.15% on the daily unused portion of the line of credit is allocated among the participating portfolios and funds at the end of each quarter. In connection with the renewal of the agreement in October 2023, an arrangement fee of $150,000 was incurred that was allocated to the participating portfolios and funds. Because the line of credit is not available exclusively to the Fund, it may be unable to borrow some or all of its requested amounts at any particular time.

The Fund had no borrowings outstanding pursuant to its line of credit at March 31, 2024. The Fund did not have any significant borrowings or allocated fees during the six months ended March 31, 2024.

8  Affiliated Investments

The Fund has invested a portion of its assets in notes (the Notes) issued by Calvert Impact Capital, Inc. (CIC) pursuant to exemptive relief granted by the U.S. Securities and Exchange Commission (the SEC). There are certain potential points of affiliation between the Fund and CIC. CRM has licensed use of the Calvert name to CIC and provides other types of support. An officer of CRM's affiliate serves on the CIC Board.

At March 31, 2024, the value of the Fund's investment in the Notes and in issuers and funds that may be deemed to be affiliated was $22,175,135, which represents 2.5% of the Fund's net assets. Transactions in such investments by the Fund for the six months ended March 31, 2024 were as follows:

Name	Value, beginning of period	Purchases	Sales proceeds	Net realized gain (loss)	Change in unrealized appreciation (depreciation)	Value, end of period	Interest/ Dividend income	Principal amount/ Shares, end of period
Commercial Mortgage-Backed Securities
Morgan Stanley Capital I Trust, Series 2019-BPR, Class A, 7.318%, (1 mo. SOFR + 1.992%), 5/15/36	$ 1,077,242	$   —	$     (38,471)	$  —	$  30,704	$  1,070,597	$  43,121	$  1,077,727
High Social Impact Investments
Calvert Impact Capital, Inc., Community Investment Notes, 1.50%, 12/15/23	246,573	—	(250,000)	—	3,427	—	771	—
Calvert Impact Capital, Inc., Community Investment Notes, 5.00%, 12/15/28(1)	—	2,000,000	—	—	(27,420)	1,972,580	29,444	2,000,000

26

Calvert

Core Bond Fund

March 31, 2024

Notes to Financial Statements (Unaudited) — continued

Name	Value, beginning of period	Purchases	Sales proceeds	Net realized gain (loss)	Change in unrealized appreciation (depreciation)	Value, end of period	Interest/ Dividend income	Principal amount/ Shares, end of period
Short-Term Investments
Liquidity Fund	$17,004,514	$282,661,158	$(280,533,714)	$  —	$  —	$ 19,131,958	$ 424,137	19,131,958
Total				$ —	$  6,711	$22,175,135	$497,473

    

(1)	Restricted security.

9  Capital Shares

The Fund’s Declaration of Trust permits the Trustees to issue an unlimited number of full and fractional shares of beneficial interest (without par value). Such shares may be issued in a number of different series (such as the Fund) and classes.

Transactions in capital shares were as follows:

	Six Months Ended March 31, 2024 (Unaudited)			Year Ended September 30, 2023(1)
	Shares	Amount		Shares	Amount
Class A
Shares sold	1,571,568	$ 24,493,737		1,810,561	$ 28,483,404
Reinvestment of distributions	74,576	1,161,519		105,364	1,656,891
Shares redeemed	(573,777)	(8,923,452)		(775,109)	(12,199,908)
Net increase	1,072,367	$ 16,731,804		1,140,816	$ 17,940,387
Class I
Shares sold	20,357,235	$ 318,141,860		35,769,030	$ 566,118,084
Reinvestment of distributions	844,966	13,186,174		840,411	13,207,704
Shares redeemed	(12,462,893)	(194,197,198)		(6,474,694)	(101,978,513)
Net increase	8,739,308	$ 137,130,836		30,134,747	$ 477,347,275
Class R6
Shares sold	5,090,637	$ 79,593,410		3,166	$ 50,000
Reinvestment of distributions	26,472	415,466		36	553
Shares redeemed	(249,623)	(3,909,599)		—	—
Net increase	4,867,486	$ 76,099,277		3,202	$ 50,553

    

(1)	For Class R6, for the period from the commencement of operations, June 30, 2023, to September 30, 2023.

27

Calvert

Core Bond Fund

March 31, 2024

Officers and Trustees

Officers

Hope L. Brown Chief Compliance Officer

Deidre E. Walsh Secretary, Vice President and Chief Legal Officer

James F. Kirchner Treasurer

Trustees

Alice Gresham Bullock Chairperson

Cari M. Dominguez

Karen Fang

Miles D. Harper, III

Von M. Hughes*(1)

Joy V. Jones

Eddie Ramos

Anthony A. Williams

* Interested Trustee and President

(1) Mr. Hughes began serving as Trustee effective December 11, 2023.

28

Calvert Funds

U.S. Customer Privacy Notice

March 2024

FACTS

WHAT DOES CALVERT DO WITH YOUR PERSONAL INFORMATION?

    

Why?	Financial companies choose how they share your personal information. Federal law gives consumers the right to limit some but not all sharing. Federal law also requires us to tell you how we collect, share, and protect your personal information. Please read this notice carefully to understand what we do.
What?	The types of personal information we collect and share depend on the product or service you have with us. This information can include: ■ Social Security number and income ■ investment experience and risk tolerance ■ checking account information and wire transfer instructions
How?	All financial companies need to share customers’ personal information to run their everyday business. In the section below, we list the reasons financial companies can share their customers’ personal information; the reasons Calvert chooses to share; and whether you can limit this sharing.

    

Reasons we can share your personal information	Does Calvert share?	Can you limit this sharing?
For our everyday business purposes — such as to process your transactions, maintain your account(s), respond to court orders and legal investigations, or report to credit bureaus	Yes	No
For our marketing purposes — to offer our products and services to you	Yes	No
For joint marketing with other financial companies	No	We don’t share
For our affiliates’ everyday business purposes — information about your transactions and experiences	Yes	No*
For our affiliates’ everyday business purposes — information about your creditworthiness	Yes	Yes*
For our affiliates to market to you	Yes	Yes*
For nonaffiliates to market to you	No	We don’t share

    

To limit our sharing	Call toll-free 1-800-368-2745 or email: CRMPrivacy@calvert.com Please note: If you are a new customer, we can begin sharing your information 30 days from the date we sent this notice. When you are no longer our customer, we continue to share your information as described in this notice. However, you can contact us at any time to limit our sharing.
Questions?	Call toll-free 1-800-368-2745 or email: CRMPrivacy@calvert.com

    

29

Calvert Funds

U.S. Customer Privacy Notice — continued

March 2024

Page 2

Who we are
Who is providing this notice?	Calvert Research and Management and our investment management affiliates (“Calvert”) (see Affiliates definition below.)
What we do
How does Calvert protect my personal information?	To protect your personal information from unauthorized access and use, we use security measures that comply with federal law. These measures include computer safeguards and secured files and buildings. We have policies governing the proper handling of customer information by personnel and requiring third parties that provide support to adhere to appropriate security standards with respect to such information.
How does Calvert collect my personal information?	We collect your personal information, for example, when you ■ open an account or make deposits or withdrawals from your account ■ buy securities from us or make a wire transfer ■ give us your contact information We also collect your personal information from others, such as credit bureaus, affiliates, or other companies.
Why can’t I limit all sharing?	Federal law gives you the right to limit only ■ sharing for affiliates’ everyday business purposes — information about your creditworthiness ■ affiliates from using your information to market to you ■ sharing for nonaffiliates to market to you State laws and individual companies may give you additional rights to limit sharing. (See below for more on your rights under state law.)
What happens when I limit sharing for an account I hold jointly with someone else?	Your choices will apply to everyone on your account.
Definitions
Affiliates	Companies related by common ownership or control. They can be financial and nonfinancial companies. ■ Our affiliates include registered investment advisers such as Eaton Vance Management, Eaton Vance Advisers International Ltd., Boston Management and Research, Parametric Portfolio Associates LLC, Atlanta Capital Management Company LLC, Morgan Stanley Investment Management Inc., Morgan Stanley Investment Management Co.; registered broker-dealers such as Morgan Stanley Distributors Inc. and Eaton Vance Distributors, Inc. (together, the “Investment Management Affiliates”); and companies with a Morgan Stanley name and financial companies such as Morgan Stanley Smith Barney LLC and Morgan Stanley & Co. (the “Morgan Stanley Affiliates”).
Nonaffiliates	Companies not related by common ownership or control. They can be financial and nonfinancial companies. ■ Calvert Research and Management does not share with nonaffiliates so they can market to you.
Joint marketing	A formal agreement between nonaffiliated financial companies that together market financial products or services to you. ■ Calvert Research and Management does not jointly market.

30

Calvert Funds

U.S. Customer Privacy Notice — continued

March 2024

Page 3

Other important information

*PLEASE NOTE: Calvert does not share your creditworthiness information or your transactions and experiences information with the Morgan Stanley Affiliates, nor does Calvert enable the Morgan Stanley Affiliates to market to you. Your opt outs will prevent Calvert from sharing your creditworthiness information with the Investment Management Affiliates and will prevent the Investment Management Affiliates from marketing their products to you. Vermont: Except as permitted by law, we will not share personal information we collect about Vermont residents with Nonaffiliates unless you provide us with your written consent to share such information. California: Except as permitted by law, we will not share personal information we collect about California residents with Nonaffiliates and we will limit sharing such personal information with our Affiliates to comply with California privacy laws that apply to us.

31

Calvert Funds

IMPORTANT NOTICES

Delivery of Shareholder Documents. The Securities and Exchange Commission (SEC) permits funds to deliver only one copy of shareholder documents, including prospectuses, proxy statements and shareholder reports, to fund investors with multiple accounts at the same residential or post office box address. This practice is often called “householding” and it helps eliminate duplicate mailings to shareholders. Calvert funds, or your financial intermediary, may household the mailing of your documents indefinitely unless you instruct Calvert funds, or your financial intermediary, otherwise. If you would prefer that your Calvert fund documents not be householded, please contact Calvert funds at 1-800-368-2745, or contact your financial intermediary. Your instructions that householding not apply to delivery of your Calvert fund documents will typically be effective within 30 days of receipt by Calvert funds or your financial intermediary.

Portfolio Holdings. Each Calvert fund files a schedule of portfolio holdings on Part F to Form N-PORT with the SEC. Certain information filed on Form N-PORT may be viewed on the Calvert website at www.calvert.com, by calling Calvert at 1-800-368-2745 or in the EDGAR database on the SEC’s website at www.sec.gov.

Proxy Voting. The Proxy Voting Guidelines that each Calvert fund uses to determine how to vote proxies relating to portfolio securities is provided as an Appendix to the fund’s Statement of Additional Information. The Statement of Additional Information can be obtained free of charge by calling the Calvert funds at 1-800-368-2745, by visiting the Calvert funds’ website at www.calvert.com or visiting the SEC’s website at www.sec.gov. Information regarding how a Calvert fund voted proxies relating to portfolio securities during the most recent 12-month period ended June 30 is available by calling Calvert funds, by visiting the Calvert funds’ website at www.calvert.com or by visiting the SEC’s website at www.sec.gov.

Tailored Shareholder Reports. Effective January 24, 2023, the SEC adopted rule and form amendments to require open-end mutual funds and ETFs to transmit concise and visually engaging streamlined annual and semiannual reports to shareholders that highlight key information. Other information, including financial statements, will no longer appear in a streamlined shareholder report but must be available online, delivered free of charge upon request, and filed on a semiannual basis on Form N-CSR. The rule and form amendments have a compliance date of July 24, 2024. At this time, management is evaluating the impact of these amendments on the shareholder reports for the Calvert Funds.

32

Investment Adviser and Administrator

Calvert Research and Management

2050 M Street NW, Suite 200

Washington, DC 20036

Principal Underwriter*

Eaton Vance Distributors, Inc.

One Post Office Square

Boston, MA 02109

(617) 482-8260

Custodian

State Street Bank and Trust Company

One Congress Street, Suite 1

Boston, MA 02114-2016

Transfer Agent

SS&C Global Investor & Distribution Solutions, Inc.

2000 Crown Colony Drive

Quincy, MA 02169

Fund Offices

2050 M Street NW, Suite 200

Washington, DC 20036

Printed on recycled paper.

24182     3.31.24

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Calvert

Income Fund

Semiannual Report

March 31, 2024

Commodity Futures Trading Commission Registration. The Commodity Futures Trading Commission (“CFTC”) has adopted regulations that subject registered investment companies and advisers to regulation by the CFTC if a fund invests more than a prescribed level of its assets in certain CFTC-regulated instruments (including futures, certain options and swap agreements) or markets itself as providing investment exposure to such instruments. The adviser has claimed an exclusion from the definition of “commodity pool operator” under the Commodity Exchange Act with respect to its management of the Fund and the other funds it manages. Accordingly, neither the Fund nor the adviser is subject to CFTC regulation.

Fund shares are not insured by the FDIC and are not deposits or other obligations of, or guaranteed by, any depository institution. Shares are subject to investment risks, including possible loss of principal invested.

This report must be preceded or accompanied by a current summary prospectus or prospectus. Before investing, investors should consider carefully the investment objective, risks, and charges and expenses of a mutual fund. This and other important information is contained in the summary prospectus and prospectus, which can be obtained from a financial intermediary. Prospective investors should read the prospectus carefully before investing. For further information, please call 1-800-368-2745.

Choose Planet-friendly E-delivery!

Sign up now for on-line statements, prospectuses, and fund reports. In less than five minutes you can help reduce paper mail and lower fund costs.

Just go to www.calvert.com. If you already have an online account with the Calvert funds, click on Login to access your Account and select the documents you would like to receive via e-mail.

If you’re new to online account access, click on Login, then Register to create your user name and password. Once you’re in, click on the E-delivery sign-up on the Account Portfolio page and follow the quick, easy steps.

Note: If your shares are not held directly with the Calvert funds but through a brokerage firm, you must contact your broker for electronic delivery options available through their firm.

Semiannual Report March 31, 2024

Calvert

Income Fund

Table of Contents
Performance	2
Fund Profile	3
Endnotes and Additional Disclosures	4
Fund Expenses	5
Financial Statements	6
Officers and Trustees	33
U.S. Customer Privacy Notice	34
Important Notices	37

Calvert

Income Fund

March 31, 2024

Performance

Portfolio Manager(s) Vishal Khanduja, CFA and Brian S. Ellis, CFA, each of Calvert Research and Management

% Average Annual Total Returns1,2	Class Inception Date	Performance Inception Date	Six Months	One Year	Five Years	Ten Years
Class A at NAV	10/12/1982	10/12/1982	8.45%	5.39%	1.95%	2.51%
Class A with 3.25% Maximum Sales Charge	—	—	4.96	1.96	1.27	2.17
Class C at NAV	07/31/2000	10/12/1982	8.05	4.67	1.18	1.89
Class C with 1% Maximum Deferred Sales Charge	—	—	7.05	3.67	1.18	1.89
Class I at NAV	02/26/1999	10/12/1982	8.64	5.72	2.20	2.87
Class R6 at NAV	02/01/2023	10/12/1982	8.67	5.77	2.22	2.87
Bloomberg U.S. Credit Index	—	—	7.71%	4.15%	1.39%	2.49%

    

% Total Annual Operating Expense Ratios3	Class A	Class C	Class I	Class R6
	0.93%	1.68%	0.68%	0.63%

See Endnotes and Additional Disclosures in this report.

Past performance is no guarantee of future results. Returns are historical and are calculated by determining the percentage change in net asset value (NAV) or offering price (as applicable) with all distributions reinvested. Furthermore, returns do not reflect the deduction of taxes that shareholders may have to pay on Fund distributions or upon the redemption of Fund shares. Investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Performance for periods less than or equal to one year is cumulative. Performance is for the stated time period only; due to market volatility, current Fund performance may be lower or higher than the quoted return. For performance as of the most recent month-end, please refer to www.calvert.com.

2

Calvert

Income Fund

March 31, 2024

Fund Profile

3

Calvert

Income Fund

March 31, 2024

Endnotes and Additional Disclosures

1	Bloomberg U.S. Credit Index measures the performance of investment-grade U.S. corporate securities and government-related bonds with a maturity of one year or more. Unless otherwise stated, index returns do not reflect the effect of any applicable sales charges, commissions, expenses, taxes or leverage, as applicable. It is not possible to invest directly in an index.
2	Total Returns at NAV do not include applicable sales charges. If sales charges were deducted, the returns would be lower. Total Returns shown with maximum sales charge reflect the stated maximum sales charge. Unless otherwise stated, performance does not reflect the deduction of taxes on Fund distributions or redemptions of Fund shares. Performance prior to the inception date of a class may be linked to the performance of an older class of the Fund. This linked performance is adjusted for any applicable sales charge, but is not adjusted for class expense differences. If adjusted for such differences, the performance would be different. The performance of Class R6 is linked to Class I. Performance since inception for an index, if presented, is the performance since the Fund’s or oldest share class's inception, as applicable. Performance presented in the Financial Highlights included in the financial statements is not linked. Effective November 5, 2020, Class C shares automatically convert to Class A shares eight years after purchase. The average annual total returns listed for Class C reflect conversion to Class A shares after eight years. Prior to November 5, 2020, Class C shares automatically converted to Class A shares ten years after purchase. Calvert Research and Management became the investment adviser to the Fund on December 31, 2016. Performance reflected prior to such date is that of the Fund’s former investment adviser.
3	Source: Fund prospectus. The expense ratios for the current reporting period can be found in the Financial Highlights section of this report. Performance reflects expenses waived and/or reimbursed, if applicable. Without such waivers and/or reimbursements, performance would have been lower.

Fund profile subject to change due to active management.

4

Calvert

Income Fund

March 31, 2024

Fund Expenses

Example

As a Fund shareholder, you incur two types of costs: (1) transaction costs, including sales charges (loads) on purchases; and (2) ongoing costs, including management fees; distribution and/or service fees; and other Fund expenses. This Example is intended to help you understand your ongoing costs (in dollars) of Fund investing and to compare these costs with the ongoing costs of investing in other mutual funds. The Example is based on an investment of $1,000 invested at the beginning of the period and held for the entire period (October 1, 2023 to March 31, 2024).

Actual Expenses

The first section of the table below provides information about actual account values and actual expenses. You may use the information in this section, together with the amount you invested, to estimate the expenses that you paid over the period. Simply divide your account value by $1,000 (for example, an $8,600 account value divided by $1,000 = 8.6), then multiply the result by the number in the first section under the heading entitled “Expenses Paid During Period” to estimate the expenses you paid on your account during this period.

Hypothetical Example for Comparison Purposes

The second section of the table below provides information about hypothetical account values and hypothetical expenses based on the actual Fund expense ratio and an assumed rate of return of 5% per year (before expenses), which is not the actual Fund return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing costs of investing in the Fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of the other funds.

Please note that the expenses shown in the table are meant to highlight your ongoing costs only and do not reflect any transactional costs, such as sales charges (loads). Therefore, the second section of the table is useful in comparing ongoing costs only, and will not help you determine the relative total costs of owning different funds. In addition, if these transactional costs were included, your costs would be higher.

	Beginning Account Value (10/1/23)	Ending Account Value (3/31/24)	Expenses Paid During Period* (10/1/23 – 3/31/24)	Annualized Expense Ratio
Actual
Class A	$1,000.00	$1,084.50	$4.79	0.92%
Class C	$1,000.00	$1,080.50	$8.69	1.67%
Class I	$1,000.00	$1,086.40	$3.49	0.67%
Class R6	$1,000.00	$1,086.70	$3.13	0.60%
Hypothetical
(5% return per year before expenses)
Class A	$1,000.00	$1,020.40	$4.65	0.92%
Class C	$1,000.00	$1,016.65	$8.42	1.67%
Class I	$1,000.00	$1,021.65	$3.39	0.67%
Class R6	$1,000.00	$1,022.00	$3.03	0.60%

    

*

Expenses are equal to the Fund's annualized expense ratio for the indicated Class, multiplied by the average account value over the period, multiplied by 183/366 (to reflect the one-half year period). The Example assumes that the $1,000 was invested at the net asset value per share determined at the close of business on September 30, 2023.

5

Calvert

Income Fund

March 31, 2024

Schedule of Investments (Unaudited)

Calvert

Income Fund

March 31, 2024

Schedule of Investments (Unaudited) — continued

Calvert

Income Fund

March 31, 2024

Schedule of Investments (Unaudited) — continued