GJM Gmac Llc 7.35% Notes Due 8/8/2032

 
November 28, 2012

Before you invest, you may want to review the Fund's statutory prospectus (and any supplements thereto), which contains more information about the Fund and its risks. You can find the Fund's statutory prospectus and other information about the Fund, including its statement of additional information and most recent reports to shareholders online at delawareinvestments.com/literature. You can also get this information at no cost by calling 800 523-1918. The Fund's statutory prospectus and statement of additional information, both dated November 28, 2012 (and any supplements thereto), are incorporated by reference into this summary prospectus.

Delaware Inflation Protected Bond Fund seeks to provide inflation protection and current income.

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales-charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in Delaware Investments ^® Funds. More information about these and other discounts is available from your financial advisor, in the Fund's prospectus under the section entitled "About your account," and in the Fund's statement of additional information under the section entitled "Purchasing shares."

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 and reflects the applicable waivers and reimbursements for the 1-year contractual period and the total operating expenses without waivers for years 2 through 10. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

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 fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 225% of the average value of its portfolio.

Under normal circumstances, the Manager will invest at least 80% of its net assets in inflation-indexed bonds issued by the U.S. government, its agencies or instrumentalities, foreign governments, and corporations, and in synthetic investments such as options, forwards, futures contracts, or swap agreements that, when combined with non-inflation-indexed bonds, have economic characteristics similar to inflation-indexed bonds. This policy is not a fundamental policy and can be changed without shareholder approval. However, shareholders would be given at least 60 days' notice prior to any change in this policy. We will seek to maintain the Fund's interest rate sensitivity at a level approximating that of the Barclays U.S. Treasury Inflation-Protected Securities (TIPS) Index. Subject to liquidity restrictions, the Fund may invest assets in derivative instruments that have economic characteristics that are similar to inflation-protected bonds.

Investing in any mutual fund involves the risk that you may lose part or all of the money you invest. Over time, the value of your investment in the Fund will increase and decrease according to changes in the value of the securities in the Fund's portfolio. Principal risks include:

Investments not guaranteed by the Manager or its affiliates  — Investments in the Fund are not and will not be deposits with or liabilities of Macquarie Bank Limited ABN 46 008 583 542 and its holding companies, including their subsidiaries or related companies (Macquarie Group), and are subject to investment risk, including possible delays in repayment and loss of income and capital invested. No Macquarie Group company guarantees or will guarantee the performance of the Fund, the repayment of capital from the Fund, or any particular rate of return.

Market risk  — The risk that all or a majority of the securities in a certain market — such as the stock or bond market — will decline in value because of factors such as adverse political or economic conditions, future expectations, investor confidence, or heavy institutional selling.

Interest rate risk  — The risk that securities will decrease in value if interest rates rise. This risk is generally associated with bonds.

Credit risk  — The risk that an issuer of a debt security, including a governmental issuer, may be unable to make interest payments and repay principal in a timely manner.

Liquidity risk  — The possibility that securities cannot be readily sold within seven days at approximately the price at which a fund has valued them.

Bank loans and other indebtedness   risk — The risk that the portfolio will not receive payment of principal, interest, and other amounts due in connection with these investments and will depend primarily on the financial condition of the borrower and the lending institution.

Prepayment risk  — The risk that the principal on a bond that is held by a portfolio will be prepaid prior to maturity at a time when interest rates are lower than what that bond was paying. A portfolio may then have to reinvest that money at a lower interest rate.

Foreign risk  — The risk that foreign securities (particularly in emerging markets) may be adversely affected by political instability; changes in currency exchange rates; inefficient markets and higher transaction costs; foreign economic conditions; or inadequate or different regulatory and accounting standards.

Forward foreign currency risk  — The use of forward foreign currency exchange contracts may substantially change a fund's exposure to currency exchange rates and could result in losses to the fund if currencies do not perform as the Manager expects. The use of these investments as a hedging technique to reduce a fund's exposure to currency risks may also reduce its ability to benefit from favorable changes in currency exchange rates.

Derivatives risk  — Derivative contracts, such as options, futures and swaps, may involve additional expenses (such as the payment of premiums) and are subject to significant loss if a security, or a securities index to which a derivative contract is associated, moves in the opposite direction from what the portfolio manager anticipated.

Counterparty risk  — The risk that a counterparty to a derivative contract (such as a swap, futures, or options contract) or a repurchase agreement may fail to perform its obligations under the contract or agreement due to financial difficulties (such as a bankruptcy or reorganization).

Government and regulatory risk  — The risk that governments or regulatory authorities have, from time to time, taken or considered actions that could adversely affect various sectors of the securities markets.

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for 1-year, 5-year, and lifetime periods compare with those of a broad measure of market performance. The Fund's past performance (before and after taxes) is not necessarily an indication of how it will perform in the future. The returns reflect expense caps in effect during these periods. The returns would be lower without the expense caps. Applicable sales charges are reflected in the average annual total returns table below. You may obtain the Fund's most recently available month-end performance by calling 800 523-1918 or by visiting our website at delawareinvestments.com/performance.

As of September 30, 2012, the Fund's Class A shares had a calendar year-to-date return of 5.87%. During the periods illustrated in this bar chart, Class A's highest quarterly return was 6.02% for the quarter ended March 31, 2008 and its lowest quarterly return was -2.87% for the quarter ended September 30, 2008. The maximum Class A sales charge of 4.50%, which is normally assessed when you purchase shares, is not reflected in the highest/lowest quarterly returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual total returns in the table below do include the sales charge.

*  Because the Fund has combined its retail and institutional prospectuses, the bar chart and the after tax returns in the average annual total returns table show the performance of the Fund's Class A shares.

After-tax performance is presented only for Class A shares of the Fund. The after-tax returns for other Fund classes may vary. Actual after-tax returns depend on the investor's individual tax situation and may differ from the returns shown. After-tax returns are not relevant for shares held in tax-deferred investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes.

Delaware Management Company, a series of Delaware Management Business Trust

You may purchase or redeem shares of the Fund on any day that the New York Stock Exchange (NYSE) is open for business (Business Day). Shares may be purchased or redeemed: through your financial advisor; through the Fund's website at delawareinvestments.com; by calling
800 523-1918; by regular mail (c/o Delaware Investments, P.O. Box 9876, Providence, RI 02940-8076); by overnight courier service (c/o Delaware Service Center, 4400 Computer Drive, Westborough, MA 01581-1722); or by wire. Please refer to the Fund's prospectus and statement of additional information for more details regarding the purchase and sale of Fund shares.

For Class A and Class C shares, the minimum initial investment is generally $1,000 and subsequent investments can be made for as little as $100. The minimum initial investment for IRAs, Uniform Gifts/Transfers to Minors Act accounts, direct deposit purchase plans and automatic investment plans is $250 and through Coverdell Education Savings Accounts is $500, and subsequent investments in these accounts can be made for as little as $25. For Institutional Class shares, there is no minimum initial purchase requirement, but certain eligibility requirements must be met. The eligibility requirements are described in the prospectus under "Choosing a share class" and on the Fund's website. We may reduce or waive the minimums or eligibility requirements in certain cases. No new or subsequent investments currently are allowed in the Fund's Class B shares, except through a reinvestment of dividends or capital gains or permitted exchanges.

The Fund's distributions generally are taxable to you as ordinary income, capital gains, or some combination of both, unless you are investing through a tax-deferred arrangement, such as a 401(k) plan or an IRA.

If you purchase shares of the Fund through a broker/dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker/dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary's website for more information.

SMPR-556 [7/12] DG3 18226 [11/12]