Strategy. The Fund typically invests at least 80% of its net assets in investment grade, U.S. dollar-denominated debt securities, as assessed at the time of purchase (the 80% Policy). For purposes of the Funds 80% Policy, net assets include any borrowings for investment purposes. A debt security is considered investment grade when assigned a credit quality rating of BBB- or higher by S&P Global Ratings (S&P) or an equivalent rating by another nationally recognized statistical rating organization (NRSRO), including Moodys Investors Service, Inc. or Fitch Ratings, or Kroll Bond Rating Agency, LLC for securitized debt instruments only (such as asset-backed securities (ABS) and mortgage-backed securities (MBS)) or if unrated, considered to be of comparable credit quality by the Funds investment adviser. … Show more… The Fund typically invests at least 80% of its net assets in investment grade, U.S. dollar-denominated debt securities, as assessed at the time of purchase (the 80% Policy). For purposes of the Funds 80% Policy, net assets include any borrowings for investment purposes. A debt security is considered investment grade when assigned a credit quality rating of BBB- or higher by S&P Global Ratings (S&P) or an equivalent rating by another nationally recognized statistical rating organization (NRSRO), including Moodys Investors Service, Inc. or Fitch Ratings, or Kroll Bond Rating Agency, LLC for securitized debt instruments only (such as asset-backed securities (ABS) and mortgage-backed securities (MBS)) or if unrated, considered to be of comparable credit quality by the Funds investment adviser. For purposes of rating restrictions, if securities are rated differently by two or more rating agencies, the highest rating is used. The Fund invests principally in bonds issued by ?U.S. corporations, the U.S. Government or its agencies, and U.S. government-sponsored enterprises (GSEs) such as the Federal National Mortgage Association (FNMA) and the Federal Home Loan Mortgage Corporation (FHLMC). The Fund also may invest in trust preferred securities, taxable municipal obligations and loans. The Fund may invest in ?ABS and MBS that represent interests in pools of mortgage loans (MBS) or other assets (ABS) assembled for sale to investors by various U.S. governmental agencies, government-related organizations and private issuers. MBS may include collateralized mortgage obligations (CMOs) and commercial mortgage-backed securities (CMBS). The Fund may invest up to 5% of its net assets in below-investment grade, high-yield debt instruments (commonly known as junk bonds), as assessed at time of purchase, including distressed instruments that are in default. The Fund may also invest up to 25% of its net assets in U.S. dollar-denominated foreign debt securities and American Depositary Receipts (ADRs), which are either sponsored or unsponsored. The Fund may purchase securities on a when-issued basis and for future delivery by means of forward commitments. The Fund may, at times, engage in derivatives transactions (such as options, swapstions, interest rate swaps, forward rate contracts, futures contracts and options thereon, forward foreign currency exchange contracts and credit derivatives) to seek to hedge against fluctuations in securities prices, interest rates or currency exchanges rates, to seek to enhance returns or as a substitute for purchasing or selling securities or currencies. Permitted credit derivatives include credit default swaps, total return swaps and credit options. Except as required by applicable regulation, there is no stated limit on the Funds use of derivatives for such purposes. The Fund may invest in money market instruments. The Fund may also lend its securities. Under normal circumstances, the Fund will have a dollar-weighted average effective portfolio maturity of between four and ten years. The Funds dollar-weighted average effective portfolio maturity may be longer or shorter for temporary purposes and during unusual market conditions. Investment decisions for the Fund are made primarily on the basis of fundamental and quantitative research conducted by the investment advisers research staff and consideration of the responsible investment criteria described below. Management of the Fund involves consideration of numerous factors (such as quality of business franchises, financial strength, management quality and security structural and collateral considerations). The portfolio managers may also use sector rotation and relative value strategies in their management of the Fund. The portfolio managers may sell a security when the investment advisers valuation target is reached, the fundamentals of the investment change or to pursue more attractive investment options. A security will also be sold (in accordance with the investment advisers guidelines and at a time and in a manner that is determined to be in the best interests of shareholders) if the investment adviser determines that the issuer does not operate in a manner consistent with the Funds responsible investment criteria. The portfolio managers intend to focus on risk management and also seek to preserve capital to the extent consistent with the Funds investment objective. The Fund intends to seek to manage investment risk by maintaining broad issuer and industry diversification among its holdings, and by utilizing fundamental analysis of risk/return characteristics in securities selection. The Fund seeks to manage duration and any hedging of interest rate risk through the purchase and sale of U.S. Treasury securities and related futures contracts (which are a type of derivative instrument). Responsible Investing. The portfolio manager(s) seek to invest in companies that manage environmental, social and governance (ESG) risk exposures adequately and that are not exposed to excessive ESG risk through their principal business activities. Companies are analyzed by the investment advisers ESG analysts utilizing The Calvert Principles for Responsible Investment (Principles), a framework for considering ESG factors (a copy of which is included as an appendix to the Funds Prospectus). Each company is evaluated relative to an appropriate peer group based on material ESG factors as determined by the investment adviser. Pursuant to the Principles, the investment adviser seeks to identify companies and other issuers that operate in a manner that is consistent with or promotes environmental sustainability and resource efficiency, equitable societies and respect for human rights, and accountable governance and transparency. The Fund generally invests in issuers that are believed by the investment adviser to operate in accordance with the Principles and may also invest in issuers that the investment adviser believes are likely to operate in accordance with the Principles pending the investment advisers engagement activity with such issuer. Show less