EATON VANCE AMT-FREE MUNICIPAL INCOME FUND (the “Fund”)

Supplement to Summary Prospectus and Prospectus dated February 1, 2026

as may be supplemented and/or revised from time to time

The Board of Trustees of Eaton Vance Mutual Funds Trust, on behalf of the Fund, approved certain changes to its expense reimbursement agreement effective July 1, 2026. Accordingly, as of July 1, 2026, the Fund’s Summary Prospectus and Prospectus are hereby amended as follows:”

The section of the Summary Prospectus entitled “Fees and Expenses of the Fund” and the section of the Prospectus entitled “Fund Summaries – AMT-Free Municipal Income Fund - Fees and Expenses of the Fund” are hereby deleted in their entirety and replaced with the following:

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Investors may also pay commissions or other fees to their financial intermediary, which are not reflected below. You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $100,000 in Eaton Vance funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A – Financial Intermediary Sales Charge Variations in the Fund’s Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 55 of the Fund’s Prospectus and page 22 of the Fund’s Statement of Additional Information.

Shareholder Fees (fees paid directly from your investment)

	Class A	Class C	Class I
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	3.25%	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at time of purchase or redemption)	None¹	1.00%	None

Class A shares purchased at net asset value in amounts of $500,000 or more are subject to a 0.75% contingent deferred sales charge if redeemed within 12 months of purchase.

Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment)

	Class A	Class C	Class I
Management Fees	0.44%	0.44%	0.44%
Distribution and Service (12b-1) Fees	0.25%	1.00%	None
Other Expenses	0.22%	0.22%	0.22%
Interest Expense	0.06%	0.06%	0.06%
Expenses other than Interest Expense	0.16%	0.16%	0.16%
Total Annual Fund Operating Expenses	0.91%	1.66%	0.66%
Expense Reimbursement¹	-0.08%	-0.08%	-0.08%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.83%	1.58%	0.58%

The investment adviser and administrator have agreed to reimburse the Fund’s expenses to the extent that Total Annual Fund Operating Expenses exceed 0.77% for Class A shares, 1.52% for Class C shares and 0.52% for Class I shares. This expense reimbursement will continue through February 1, 2028. Any amendment to or termination of this reimbursement would require approval of the Board of Trustees. The expense reimbursement relates to ordinary operating expenses only and does not include expenses such as: brokerage commissions, acquired fund fees and expenses of unaffiliated funds, borrowing costs (including borrowing costs of any acquired funds), taxes or litigation expenses. Amounts reimbursed may be recouped by the investment adviser and administrator during the same fiscal year to the extent actual expenses are less than any contractual expense cap in place during such year. Pursuant to this arrangement, the investment adviser may recoup from the Fund any reimbursed expenses during the same fiscal year if such recoupment does not cause the Fund’s Total Annual Fund Operating Expenses after such recoupment to exceed (i) the expense limit in effect at the time of the reimbursement; or (ii) the expense limit in effect at the time of recoupment.

Example. This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year, that the operating expenses remain the same and that any expense reimbursement arrangement remains in place for the contractual period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

If you SOLD Your Shares

	1 Year	3 Years	5 Years	10 Years
Class A shares	$407	$598	$805	$1,401
Class C shares	$261	$516	$895	$1,759
Class I shares	$59	$203	$360	$815

If you HELD Your Shares

	1 Year	3 Years	5 Years	10 Years
Class A shares	$407	$598	$805	$1,401
Class C shares	$161	$516	$895	$1,759
Class I shares	$59	$203	$360	$815

June 25, 2026

48687-00 6.25.26