Strategy. Investing at least 80% of assets in underlying funds that are (i)Fidelity funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity Sustainable Index Funds), and (iii)Fidelity funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity Traditional Funds) (collectively, underlying Fidelity Funds). Effective December 11, 2025, derivative instruments that provide investment exposure to the … Show more… Investing at least 80% of assets in underlying funds that are (i)Fidelity funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity Sustainable Index Funds), and (iii)Fidelity funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity Traditional Funds) (collectively, underlying Fidelity Funds). Effective December 11, 2025, 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. Evaluating each security in which a Fidelity Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG ratingsprocess.The Adviser's proprietary ESG ratings process evaluates the current state of an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and also provides a qualitative forward-looking assessment of an issuer's sustainability outlook provided by the Adviser's fundamental research analysts and ESG team.Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity Sustainable Target Date Retirement Fund, approximately 10 to 19 years after the year 2010. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. During the fourth quarter of 2025, the Adviser will begin transitioning the neutral asset allocation percentages to achieve the desired allocations. The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds.Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation.The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective.The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class.The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics.Designed for investors who retired in or within a few years of 2010 (target retirement date) at or around age 65.Fidelity Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying FidelityFunds" for additional information. When the neutral asset allocation of a fund matches Fidelity Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 10 to 19 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity Sustainable Target Date Retirement Fund. Show less