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2026-08-29 2026-08-29 0000035315 fmr:FidelitySAIEnhancedMunicipalIncomeFund-PROMember fmr:S000090604Member fmr:InterestRateChangesMember 2026-08-29 2026-08-29 0000035315 fmr:FidelitySAIEnhancedMunicipalIncomeFund-PROMember fmr:S000090604Member fmr:IssuerSpecificChangesMember 2026-08-29 2026-08-29 0000035315 fmr:FidelitySAIEnhancedMunicipalIncomeFund-PROMember fmr:S000090604Member fmr:QuantitativeInvestingMember 2026-08-29 2026-08-29 0000035315 fmr:FidelitySAIEnhancedMunicipalIncomeFund-PROMember fmr:S000090604Member oef:RiskNotInsuredDepositoryInstitutionMember 2026-08-29 2026-08-29 0000035315 fmr:FidelitySAIEnhancedMunicipalIncomeFund-PROMember fmr:S000090604Member oef:RiskLoseMoneyMember 2026-08-29 2026-08-29 iso4217:USD pure 485BPOS 2026-08-29 false 0000035315 N-1A Fidelity Salem Street Trust Fund Summary Fund: Fidelity® Mid Cap Growth Index Fund Investment Objective Fidelity® Mid Cap Growth Index Fund seeks to provide investment results that correspond to the total return of stocks of mid-capitalization U.S. companies. Fee Table The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions, which are not reflected in the tables and examples below. Shareholder fees 0 Annual Operating Expenses 0.0005 0 0.0000 0.0005 This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated: 5 16 28 64 Portfolio Turnover The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 61 % of the average value of its portfolio. 0.61 Principal Investment Strategies Normally investing at least 80% of assets in securities included in the Russell Midcap® Growth Index. The Russell Midcap ® Growth Index is a market capitalization-weighted index designed to measure the performance of the mid-cap growth segment of the U.S. equity market. It includes those Russell MidCap ® Index companies with higher price-to-book ratios and higher forecasted growth values. The Russell Midcap ® Growth Index applies a capping methodology. Index constituents are capped quarterly so that no more than 22.5% of the index weight may be allocated to a single constituent, and the sum of the weights of all constituents representing more than 4.5% of the index should not exceed 45% of the total index weight. Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Primarily using replication; however, the fund may or may not hold all of the securities in the index. Lending securities to earn income for the fund. Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty. Correlation to Index. The performance of the fund and its underlying index may vary somewhat due to factors such as fees and expenses of the fund, transaction costs, sample selection, regulatory restrictions, and timing differences associated with additions to and deletions from the index. Errors in the construction or calculation of the index may occur from time to time and may not be identified and corrected for some period of time, which may have an adverse impact on the fund and its shareholders. Passive Management Risk. The fund is managed with a passive investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the fund's index or of the actual securities included in the index. This differs from an actively managed fund, which typically seeks to outperform a benchmark index. As a result, the fund's performance could be lower than actively managed funds that may shift their portfolio assets to take advantage of market opportunities or lessen the impact of a market decline or a decline in the value of one or more issuers. "Growth" Investing. "Growth" stocks can perform differently from the market as a whole and other types of stocks and can be more volatile than other types of stocks.       Mid Cap Investing. The value of securities of medium size, less well-known issuers can perform differently from the market as a whole and other types of stocks and can be more volatile than that of larger issuers. Securities Lending Risk. Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .   You could lose money by investing in the fund. Performance The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. Past performance (before and after taxes) is not an indication of future performance. www.fidelity.com Year-by-Year Returns 0.3484 0.1271 -0.2667 0.2579 0.2202 0.0862    Highest Quarter Return 0.3008 2020-06-30    Lowest Quarter Return -0.2104 2022-06-30    Year-to-Date Return 0.0724 2026-06-30 Average Annual Returns After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. Return Before Taxes 0.0862 0.0662 0.1087 Return After Taxes on Distributions 0.0813 0.0601 0.1034 Return After Taxes on Distributions and Sale of Fund Shares 0.0542 0.0501 0.0861 Russell Midcap® Growth Index 0.0866 0.0665 0.1099 Russell 3000® Index 0.1715 0.1315 0.1468 2019-07-11 Fund Summary Fund: Fidelity® Mid Cap Value Index Fund Investment Objective Fidelity® Mid Cap Value Index Fund seeks to provide investment results that correspond to the total return of stocks of mid-capitalization U.S. companies. Fee Table The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions, which are not reflected in the tables and examples below. Shareholder fees 0 Annual Operating Expenses 0.0005 0 0.0000 0.0005 This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated: 5 16 28 64 Portfolio Turnover The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 43 % of the average value of its portfolio. 0.43 Principal Investment Strategies Normally investing at least 80% of assets in securities included in the Russell Midcap® Value Index. The Russell Midcap ® Value Index is a market capitalization-weighted index designed to measure the performance of the mid-cap value segment of the U.S. equity market. It includes those Russell MidCap ® Index companies with lower price-to-book ratios and lower forecasted growth values. The Russell Midcap ® Value Index applies a capping methodology. Index constituents are capped quarterly so that no more than 22.5% of the index weight may be allocated to a single constituent, and the sum of the weights of all constituents representing more than 4.5% of the index should not exceed 45% of the total index weight. Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Primarily using replication; however, the fund may or may not hold all of the securities in the index. Lending securities to earn income for the fund. Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty. Correlation to Index. The performance of the fund and its underlying index may vary somewhat due to factors such as fees and expenses of the fund, transaction costs, sample selection, regulatory restrictions, and timing differences associated with additions to and deletions from the index. Errors in the construction or calculation of the index may occur from time to time and may not be identified and corrected for some period of time, which may have an adverse impact on the fund and its shareholders. Passive Management Risk. The fund is managed with a passive investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the fund's index or of the actual securities included in the index. This differs from an actively managed fund, which typically seeks to outperform a benchmark index. As a result, the fund's performance could be lower than actively managed funds that may shift their portfolio assets to take advantage of market opportunities or lessen the impact of a market decline or a decline in the value of one or more issuers. "Value" Investing. "Value" stocks can perform differently from the market as a whole and other types of stocks and can continue to be undervalued by the market for long periods of time. Mid Cap Investing. The value of securities of medium size, less well-known issuers can perform differently from the market as a whole and other types of stocks and can be more volatile than that of larger issuers. Securities Lending Risk. Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .   You could lose money by investing in the fund. Performance The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. Past performance (before and after taxes) is not an indication of future performance. www.fidelity.com Year-by-Year Returns 0.0474 0.2819 -0.1207 0.1276 0.1300 0.1100    Highest Quarter Return 0.2043 2020-12-31    Lowest Quarter Return -0.3167 2020-03-31    Year-to-Date Return 0.1756 2026-06-30 Average Annual Returns After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. Return Before Taxes 0.1100 0.0978 0.0933 Return After Taxes on Distributions 0.1025 0.0873 0.0844 Return After Taxes on Distributions and Sale of Fund Shares 0.0687 0.0747 0.0722 Russell Midcap® Value Index 0.1105 0.0983 0.0943 Russell 3000® Index 0.1715 0.1315 0.1468 2019-07-11 Fund Summary Fund: Fidelity® Small Cap Growth Index Fund Investment Objective Fidelity® Small Cap Growth Index Fund seeks to provide investment results that correspond to the total return of stocks of small-capitalization U.S. companies. Fee Table The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions, which are not reflected in the tables and examples below. Shareholder fees 0 Annual Operating Expenses 0.0005 0 0.0000 0.0005 This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated: 5 16 28 64 Portfolio Turnover The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 63 % of the average value of its portfolio. 0.63 Principal Investment Strategies Normally investing at least 80% of assets in securities included in the Russell 2000® Growth Index. The Russell 2000 ® Growth Index is a market capitalization-weighted index designed to measure the performance of the small-cap growth segment of the U.S. equity market. It includes those Russell 2000 ® Index companies with higher price-to-book ratios and higher forecasted growth rates. The Russell 2000 ® Growth Index applies a capping methodology. Index constituents are capped quarterly so that no more than 22.5% of the index weight may be allocated to a single constituent, and the sum of the weights of all constituents representing more than 4.5% of the index should not exceed 45% of the total index weight. Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Primarily using replication; however, the fund may or may not hold all of the securities in the index. Lending securities to earn income for the fund. Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty. Correlation to Index. The performance of the fund and its underlying index may vary somewhat due to factors such as fees and expenses of the fund, transaction costs, sample selection, regulatory restrictions, and timing differences associated with additions to and deletions from the index. Errors in the construction or calculation of the index may occur from time to time and may not be identified and corrected for some period of time, which may have an adverse impact on the fund and its shareholders. Passive Management Risk. The fund is managed with a passive investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the fund's index or of the actual securities included in the index. This differs from an actively managed fund, which typically seeks to outperform a benchmark index. As a result, the fund's performance could be lower than actively managed funds that may shift their portfolio assets to take advantage of market opportunities or lessen the impact of a market decline or a decline in the value of one or more issuers. "Growth" Investing. "Growth" stocks can perform differently from the market as a whole and other types of stocks and can be more volatile than other types of stocks.       Small Cap Investing. The value of securities of smaller, less well-known issuers can perform differently from the market as a whole and other types of stocks and can be more volatile than that of larger issuers. Securities Lending Risk. Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .   You could lose money by investing in the fund. Performance The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. Past performance (before and after taxes) is not an indication of future performance. www.fidelity.com Year-by-Year Returns 0.3440 0.0282 -0.2617 0.1890 0.1525 0.1303    Highest Quarter Return 0.3043 2020-06-30    Lowest Quarter Return -0.2577 2020-03-31    Year-to-Date Return 0.2225 2026-06-30 Average Annual Returns After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. Return Before Taxes 0.1303 0.0329 0.0845 Return After Taxes on Distributions 0.1284 0.0288 0.0803 Return After Taxes on Distributions and Sale of Fund Shares 0.0778 0.0242 0.0660 Russell 2000® Growth Index 0.1301 0.0318 0.0838 Russell 3000® Index 0.1715 0.1315 0.1468 2019-07-11 Fund Summary Fund: Fidelity® Small Cap Value Index Fund Investment Objective Fidelity® Small Cap Value Index Fund seeks to provide investment results that correspond to the total return of stocks of small-capitalization U.S. companies. Fee Table The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions, which are not reflected in the tables and examples below. Shareholder fees 0 Annual Operating Expenses 0.0005 0 0.0000 0.0005 This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated: 5 16 28 64 Portfolio Turnover The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 41 % of the average value of its portfolio. 0.41 Principal Investment Strategies Normally investing at least 80% of assets in securities included in the Russell 2000® Value Index. The Russell 2000 ® Value Index is a market capitalization-weighted index designed to measure the performance of the small-cap value segment of the U.S. equity market. It includes those Russell 2000 ® Index companies with lower price-to-book ratios and lower forecasted growth rates. The Russell 2000 ® Value Index applies a capping methodology. Index constituents are capped quarterly so that no more than 22.5% of the index weight may be allocated to a single constituent, and the sum of the weights of all constituents representing more than 4.5% of the index should not exceed 45% of the total index weight. Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Primarily using replication; however, the fund may or may not hold all of the securities in the index. Lending securities to earn income for the fund. Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty. Correlation to Index. The performance of the fund and its underlying index may vary somewhat due to factors such as fees and expenses of the fund, transaction costs, sample selection, regulatory restrictions, and timing differences associated with additions to and deletions from the index. Errors in the construction or calculation of the index may occur from time to time and may not be identified and corrected for some period of time, which may have an adverse impact on the fund and its shareholders. Passive Management Risk. The fund is managed with a passive investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the fund's index or of the actual securities included in the index. This differs from an actively managed fund, which typically seeks to outperform a benchmark index. As a result, the fund's performance could be lower than actively managed funds that may shift their portfolio assets to take advantage of market opportunities or lessen the impact of a market decline or a decline in the value of one or more issuers. "Value" Investing. "Value" stocks can perform differently from the market as a whole and other types of stocks and can continue to be undervalued by the market for long periods of time. Small Cap Investing. The value of securities of smaller, less well-known issuers can perform differently from the market as a whole and other types of stocks and can be more volatile than that of larger issuers. Securities Lending Risk. Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .   You could lose money by investing in the fund. Performance The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. Past performance (before and after taxes) is not an indication of future performance. www.fidelity.com Year-by-Year Returns 0.0448 0.2814 -0.1443 0.1473 0.0816 0.1270    Highest Quarter Return 0.3320 2020-12-31    Lowest Quarter Return -0.3572 2020-03-31    Year-to-Date Return 0.2291 2026-06-30 Average Annual Returns After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. Return Before Taxes 0.1270 0.0893 0.0894 Return After Taxes on Distributions 0.1195 0.0772 0.0791 Return After Taxes on Distributions and Sale of Fund Shares 0.0777 0.0667 0.0681 Russell 2000® Value Index 0.1259 0.0888 0.0894 Russell 3000® Index 0.1715 0.1315 0.1468 2019-07-11 Fund Summary Fund: Fidelity® SAI Enhanced Municipal Income Fund Investment Objective Fidelity® SAI Enhanced Municipal Income Fund seeks to provide a high current yield exempt from federal income tax. Fee Table The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. Shareholder fees 0 Annual Operating Expenses 0.0020 0 0.0005 0.0025 -0.0010 0.0015 2027-10-31 This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated: 15 67 127 305 Portfolio Turnover The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 23 % of the average value of its portfolio. 0.23 Principal Investment Strategies Normally investing at least 80% of assets in municipal securities whose interest is exempt from federal income tax. The municipal securities in which the fund invests are normally investment-grade (those of medium and high quality). Municipal debt securities are issued to raise money for a variety of public and private purposes, including general financing for state and local governments, financing for eligible non-profit organizations, or financing for a specific project or public facility. Municipal debt securities in which the fund invests include securities issued by U.S. territories and possessions, general obligation bonds of municipalities, local or state governments, project or revenue-specific bonds, or pre-refunded or escrowed bonds, municipal money market securities, and synthetic securities. Municipal securities usually pay a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Investment grade securities in which the fund invests include securities or issuers rated at least BBB- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO), or, if unrated, determined by the Adviser to be of comparable quality. Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Using the Bloomberg Municipal Bond Index as a guide in structuring the fund and selecting its investments as it relates to credit quality distribution and risk characteristics. Potentially investing more than 25% of total assets in municipal securities that finance similar projects. Generally utilizing a research-driven approach identifying long-term drivers of municipal debt security returns that may include, but are not limited to, valuation, quality, momentum, and other factors. The research is systematically applied alongside a proprietary portfolio construction and risk management framework to select a broadly diversified group of debt securities that may have the potential to provide a higher total return than that of the Bloomberg Municipal Bond Index. Municipal Market Volatility. The municipal market is volatile and can be significantly affected by adverse tax, legislative, or political changes and the financial condition of the issuers of municipal securities. Interest Rate Changes. Interest rate increases can cause the price of a debt security to decrease. Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease. Quantitative Investing. Securities selected using quantitative analysis can perform differently from the market as a whole as a result of the factors used in the analysis, the weight placed on each factor, and changes in the factors' historical trends. An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .   You could lose money by investing in the fund. Performance Performance history will be available for the fund after the fund has been in operation for one calendar year. Performance history will be available for the fund after the fund has been in operation for one calendar year. A From July 11, 2019 . A From July 11, 2019 . A From July 11, 2019 . A From July 11, 2019 . A Fidelity Management & Research Company LLC (FMR) has contractually agreed to reimburse the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of its average net assets, exceed 0.15% (the Expense Cap). If at any time during the current fiscal year expenses for the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through October 31, 2027 . FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees and may extend it in its discretion after that date.