# EDGAR Filing Document

**Accession Number:** 0000910682
**File Stem:** 0001133228-26-002553
**Filing Date:** 2026-2
**Character Count:** 26810
**Document Hash:** aacb3924a91fb993b33f1961652bdc77
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001133228-26-002553.hdr.sgml**: 20260227

**ACCESSION NUMBER**: 0001133228-26-002553

**CONFORMED SUBMISSION TYPE**: 497K

**PUBLIC DOCUMENT COUNT**: 3

**FILED AS OF DATE**: 20260227

**DATE AS OF CHANGE**: 20260227

**EFFECTIVENESS DATE**: 20260227

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** DELAWARE GROUP ADVISER FUNDS
- **CENTRAL INDEX KEY:** 0000910682

**ORGANIZATION NAME:**
- **EIN:** 521842569
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1031

**FILING VALUES:**
- **FORM TYPE:** 497K
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 033-67490
- **FILM NUMBER:** 26697595

**BUSINESS ADDRESS:**
- **STREET 1:** 100 INDEPENDENCE
- **STREET 2:** 610 MARKET STREET
- **CITY:** PHILADELPHIA
- **STATE:** PA
- **ZIP:** 19106-2354
- **BUSINESS PHONE:** 18005231918

**MAIL ADDRESS:**
- **STREET 1:** 100 INDEPENDENCE
- **STREET 2:** 610 MARKET STREET
- **CITY:** PHILADELPHIA
- **STATE:** PA
- **ZIP:** 19106-2354

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** DELAWARE GROUP ADVISER FUNDS INC /MD/
- **DATE OF NAME CHANGE:** 19961202

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** DELAWARE GROUP ADVISER FUNDS INC
- **DATE OF NAME CHANGE:** 19960508

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** LINCOLN ADVISOR FUNDS INC
- **DATE OF NAME CHANGE:** 19931203

## Series and Classes Contracts Data

### Nomura Diversified Income Fund (Series ID: S000003911)

| Class ID   | Class Name          | Ticker Symbol   |
|:---|:---|:---|
| C000010956 | CLASS A             | DPDFX           |
| C000010958 | CLASS C             | DPCFX           |
| C000010959 | CLASS R             | DPRFX           |
| C000010960 | INSTITUTIONAL CLASS | DPFFX           |
| C000171464 | Class R6            | DPZRX           |

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| |
|:---|
| ![](sp2417img002.jpg)  |
| Summary prospectus |

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Fixed income mutual fund

Nomura Diversified Income Fund

(formerly, Macquarie Diversified Income Fund)

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| | |
|:---|:---|
|  | **Nasdaq ticker symbols** |
| Class A | DPDFX |
| Class C | DPCFX |
| Class R | DPRFX |
| Institutional Class | DPFFX |
| Class R6 | DPZRX |

---

February 27, 2026

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 nomuraassetmanagement.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 February 27, 2026 (and any supplements thereto), are incorporated by reference into this summary prospectus.

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| |
|:---|
| Summary prospectus |
| **Nomura Diversified Income Fund**, a series of Delaware Group<sup>®</sup> Adviser Funds<br>(formerly, Macquarie Diversified Income Fund) |

---

**What is the** **Fund's investment objective?**

Nomura Diversified Income Fund seeks maximum long-term total return, consistent with reasonable risk.

**What are the** **Fund's fees and expenses?**

The table below describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. **You may pay other fees, such as brokerage commissions and other** **fees to financial intermediaries, which are not reflected in the tables and examples below**. 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 Nomura Funds (formerly, Macquarie Funds). More information about these and other discounts is available from your financial intermediary, in the Fund's Prospectus under the section entitled "About your account," and in the Fund's statement of additional information (SAI) under the section entitled "Purchasing Shares."

**Shareholder fees (fees paid directly from your investment)**

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| | | | | | |
|:---|:---|:---|:---|:---|:---|
| Class | A | C | R | Inst. | R6 |
| &nbsp;&nbsp;Maximum sales charge (load) imposed <br>on purchases as a percentage of <br>offering price................... | 4.50% |  |  |  |  |
| &nbsp;&nbsp;Maximum contingent deferred sales <br>charge (load) as a percentage of <br>original purchase price or redemption <br>price, whichever is lower........... | none<sup>1</sup> | 1.00%<sup>1</sup> |  |  |  |

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**Annual** **fund operating expenses (expenses that you pay each year as a percentage of the** **value of your investment)**

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| | | | | | |
|:---|:---|:---|:---|:---|:---|
| Class | A | C | R | Inst. | R6 |
| Management fees................. | 0.48% | 0.48% | 0.48% | 0.48% | 0.48% |
| Distribution and service (12b-1) fees.... | 0.25% | 1.00% | 0.50% |  |  |
| Other expenses.................. | 0.16% | 0.16% | 0.16% | 0.16% | 0.06%<sup>2</sup> |
| Total annual fund operating expenses... | 0.89% | 1.64% | 1.14% | 0.64% | 0.54% |
| &nbsp;&nbsp;Fee waivers and expense <br>reimbursements................. | (0.22%)<sup>3</sup> | (0.22%)<sup>3</sup> | (0.22%)<sup>3</sup> | (0.22%)<sup>3</sup> | (0.22%)<sup>3</sup> |
| &nbsp;&nbsp;Total annual fund operating expenses <br>after fee waivers and expense <br>reimbursements................. | 0.67% | 1.42% | 0.92% | 0.42% | 0.32% |

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| | |
|:---|:---|
| 1 | For Class A shares, a 1% contingent deferred sales charge (CDSC) is only imposed on certain Class A shares that are purchased at net asset value (NAV) for $1 million or more that are subsequently redeemed within 18 months of purchase. For Class C shares, a 1% CDSC applies to redemptions within 12 months of purchase. |

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2 "Other expenses" account for Class R6 shares not being subject to certain expenses as described further in the section of this Prospectus entitled "Choosing a share class."

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| | |
|:---|:---|
| 3 | The Fund's investment manager, Delaware Management Company (Manager), has contractually agreed to waive all or a portion of its investment advisory fees and/or pay/reimburse expenses (excluding any 12b-1 fees, acquired fund fees and expenses, taxes, interest, short sale dividend and interest expenses, brokerage fees, certain insurance costs, and nonroutine expenses or costs, including, but not limited to, those relating to reorganizations, litigation, conducting shareholder meetings, and liquidations) in order to prevent total annual fund operating expenses from exceeding 0.42% of the Fund's average daily net assets for all share classes other than Class R6, and 0.32% of the Fund's Class R6 shares' average daily net assets, from February 27, 2026 through February 26, 2027. These waivers and reimbursements may only be terminated by agreement of the Manager and the Fund. |

---

**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. In addition, the example shows expenses for Class C shares, assuming those shares were not redeemed at the end of those periods. The example also assumes that your investment has a 5% return each year and reflects the Manager's expense 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:

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| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
| Class | A | (if not <br>redeemed)<br>C | C | R | Inst. | R6 |
| 1 year................... | $515 | $145 | $245 | $94 | $43 | $33 |
| 3 years................... | $700 | $496 | $496 | $340 | $183 | $151 |
| 5 years................... | $900 | $871 | $871 | $606 | $335 | $280 |
| 10 years.................. | $1477 | $1925 | $1925 | $1366 | $777 | $656 |

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**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 the 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 102% of the average value of its portfolio.

**What are the** **Fund's principal investment strategies?**

The Fund allocates its investments principally among the following four sectors of the fixed income securities markets: the US investment grade sector, the US high yield sector, the international developed markets sector, and the emerging markets sector. Under normal circumstances, the Fund will invest at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in fixed income securities (80% policy). The Manager will

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Summary prospectus<br>**Nomura Diversified Income Fund, a series of Delaware Group® Adviser Funds**<br>

determine how much of the Fund's assets to allocate to each of the four sectors, based on its evaluation of economic and market conditions, and its assessment of the returns and potential for appreciation that can be achieved from investments in each of the four sectors. Allocations of the Fund's assets among these four sectors will vary over time and the Fund may not be invested in all of these sectors at all times.

Under normal circumstances, between 5% and 35% of the Fund's net assets will be allocated to the US high yield sector. The Fund's investments in emerging markets will, in the aggregate, be limited to no more than 20% of the Fund's net assets. The Fund will limit its investments in foreign securities to between 5% and 40% of its net assets and will seek to hedge its foreign currency exposure, which will be limited to 20% of the Fund's net assets, by entering into forward foreign currency contracts.

The Fund may hold a substantial portion of its assets in cash or short-term fixed income obligations in unusual market conditions to meet redemption requests, for temporary defensive purposes, and pending investment. The Fund may invest in mortgage-backed securities and other asset-backed securities. The Fund may also use a wide range of derivatives instruments, typically including options, futures contracts, options on futures contracts, and swaps. The Fund may invest in collateralized mortgage obligations (CMOs) and real estate mortgage investment conduits (REMICs).

The Fund may also use a wide range of derivatives instruments, typically including options, futures contracts, options on futures contracts, and swaps. The Fund will use derivatives for both hedging and nonhedging purposes. For example, the Fund may invest in: futures and options to manage duration and for defensive purposes, such as to protect gains or hedge against potential losses in the portfolio without actually selling a security, or to stay fully invested; forward foreign currency contracts to manage foreign currency exposure; interest rate swaps to neutralize the impact of interest rate changes; credit default swaps to hedge against a credit event, to gain exposure to certain securities or markets, or to enhance total return; and index swaps to enhance return or to effect diversification. The Fund will not use derivatives for reasons inconsistent with its investment objective.

The Fund's 80% policy is nonfundamental and may be changed without shareholder approval. However, Fund shareholders would be given at least 60 days' notice prior to any such change.

**What are the principal risks of investing in the** **Fund?**

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. An investment in the Fund may not be appropriate for all investors. The Fund's principal risks include:

**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.

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

**High yield (junk) bond risk** — The risk that high yield securities, commonly known as "junk bonds," are subject to reduced creditworthiness of issuers, increased risk of default, and a more limited and less liquid secondary market. High yield securities may also be subject to greater price volatility and risk of loss of income and principal than are higher-rated securities.

**Interest rate risk** — The risk that the prices of bonds and other fixed income securities will increase as interest rates fall and decrease as interest rates rise. Interest rate changes are influenced by a number of factors, such as government policy, monetary policy, inflation expectations, and the supply and demand of bonds. Bonds and other fixed income securities with longer maturities or duration generally are more sensitive to interest rate changes. A fund may be subject to a greater risk of rising interest rates when interest rates are low or inflation rates are high or rising.

**Loans and other direct indebtedness risk** — The risk that a fund 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. A fund's ability to sell its loans or to realize their full value upon sale may also be impaired due to the lack of an active trading market, irregular trading activity, wide bid/ask spreads, contractual restrictions, and extended trade settlement periods. In addition, certain loans in which a fund invests may not be considered securities. A fund therefore may not be able to rely upon the anti-fraud provisions of the federal securities laws with respect to these investments.

**Mortgage-backed and asset-backed securities risk** — Mortgage-backed and asset-backed securities, like other fixed income securities, are subject to credit risk and interest rate risk, and may also be subject to prepayment risk and extension risk. Prepayment risk is the risk that the principal on mortgage-backed or asset-backed securities may be prepaid at any time, which will reduce the yield and market value of the securities and may cause the fund to reinvest the proceeds in lower yielding securities. Extension risk is the risk that principal on mortgage-backed or asset-backed securities will be repaid more slowly than expected, which may reduce the proceeds available for reinvestment in higher yielding securities. In addition, mortgage-backed and asset-backed securities may decline in value, become more volatile, face difficulties in valuation, or experience reduced liquidity due to changes in interest rates or general economic conditions. Certain mortgage-backed or asset-backed securities, such as collateralized mortgage obligations, real estate mortgage investment conduits, and stripped mortgage-backed securities, may be more susceptible to these risks than other mortgage-backed, asset-backed, or fixed-income securities.

**Foreign and emerging markets risk** — The risk that investments in foreign securities (particularly those of issuers in emerging markets) may be adversely affected by political instability; changes in currency exchange rates; inefficient markets and higher transaction costs;

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Summary prospectus<br>**Nomura Diversified Income Fund, a series of Delaware Group® Adviser Funds**<br>

foreign economic conditions; the imposition of economic or trade sanctions; or inadequate or different regulatory and accounting standards. Securities of issuers in emerging markets may be subject to greater risks than securities of issuers in more developed foreign markets because, among other things, emerging markets may have less stable political and economic environments. In addition, there often is substantially less publicly available information about issuers and such information tends to be of a lesser quality. Economic markets and structures tend to be less mature and diverse and the securities markets may also be smaller, less liquid, and subject to greater price volatility.

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

**US government securities risk** — The risk that certain US government securities, such as securities issued by Fannie Mae, Freddie Mac and the Federal Home Loan Bank system (FHLB), are not backed by the "faith and credit" of the US government and, instead, may be supported only by the credit of the issuer or by the right of the issuer to borrow from the US Treasury.

**Derivatives risk** — Derivatives contracts, such as futures, forward foreign currency contracts, options, and swaps, may involve additional expenses (such as the payment of premiums) and are subject to significant loss if a security, index, reference rate, or other asset or market factor to which a derivatives contract is associated, moves in an unanticipated direction. When used for hedging, the change in value of the derivatives instrument may also not correlate specifically with the currency, rate, or other risk being hedged, in which case a fund may not realize the intended benefits. Derivatives contracts are also subject to the risk that the counterparty may fail to perform its obligations under the contract due to, among other reasons, financial difficulties (such as a bankruptcy or reorganization).

**Leveraging risk** — The risk that certain fund transactions, such as reverse repurchase agreements, short sales, loans of portfolio securities, and the use of when-issued, delayed delivery or forward commitment transactions, or derivatives instruments, may give rise to leverage, causing a fund to be more volatile than if it had not been leveraged, which may result in increased losses to the fund.

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

**Valuation risk** — The risk that a less liquid secondary market may make it more difficult for a fund to obtain precise valuations of certain securities in its portfolio.

**Portfolio turnover risk** — High portfolio turnover rates may increase a fund's transaction costs and lower returns.

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**Government and regulatory risk** — The risk that governments or regulatory authorities may take actions that could adversely affect various sectors of the securities markets and affect fund performance.

**Active management and selection risk** — The risk that the securities selected by a fund's management will underperform the markets, the relevant indices, or the securities selected by other funds with similar investment objectives and investment strategies. The securities and sectors selected may vary from the securities and sectors included in the relevant index.

**How has** **Nomura Diversified Income Fund performed?**

The bar chart and table below provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund's performance from year to year and the table shows how the Fund's average annual total returns for the 1-, 5-, and 10-year or 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 the Fund will perform in the future. The returns reflect any expense caps in effect during these periods. The returns would be lower without the expense caps. You may obtain the Fund's most recently available month-end performance by calling 800-523-1918 or by visiting our website at nomuraassetmanagement.com/performance.

**Calendar year-by-year total return (Class A)**

![](sp2417img001.jpg)

During the periods illustrated in this bar chart, Class A's highest quarterly return was 7.42% for the quarter ended December 31, 2023, and its lowest quarterly return was -6.94% for the quarter ended June 30, 2022. The maximum Class A sales charge of 4.50%, which is normally deducted 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.

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Summary prospectus<br>**Nomura Diversified Income Fund, a series of Delaware Group® Adviser Funds**<br>

**Average annual total returns for periods ended** **December 31, 2025**

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| | | | |
|:---|:---|:---|:---|
|  | 1 year | 5 years | 10 years or<br>lifetime |
| Class A return before taxes......................... | 2.48% | -1.13% | 2.12% |
| Class A return after taxes on distributions............... | 0.68% | -2.61% | 0.70% |
| &nbsp;&nbsp;Class A return after taxes on distributions and sale of Fund <br>shares....................................... | 1.44% | -1.48% | 1.00% |
| Class C return before taxes......................... | 5.57% | -0.95% | 1.83% |
| Class R return before taxes......................... | 7.24% | -0.45% | 2.35% |
| Class R6 return before taxes (lifetime: 5/2/16–12/31/25)..... | 7.73% | 0.14% | 2.70% |
| Institutional Class return before taxes.................. | 7.63% | 0.05% | 2.86% |
| &nbsp;&nbsp;Bloomberg US Aggregate Index (reflects no deduction for <br>fees, expenses, or taxes)......................... | 7.30% | -0.36% | 2.01% |

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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-advantaged 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.

**Who manages the** **Fund?**

**Investment manager**

Delaware Management Company, a series of Nomura Investment Management Business Trust (a Delaware statutory trust)

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| | | |
|:---|:---|:---|
| **Portfolio managers** | &nbsp;&nbsp;**Title with Delaware Management Company** | &nbsp;&nbsp;**Start date on the** **Fund** |
| Janaki Rao | &nbsp;&nbsp;Managing Director, Head of US Multisector | &nbsp;&nbsp;May 2024 |
| Kashif Ishaq | &nbsp;&nbsp;Managing Director, Senior Portfolio Manager | &nbsp;&nbsp;December 2025 |
| Mansur Rasul | &nbsp;&nbsp;Executive Director, Head of Emerging Markets Debt | &nbsp;&nbsp;December 2025 |

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Employees of the Manager's affiliates outside the US participate in the management of certain funds as "associated persons" of the Manager under the Manager's oversight, in accordance with SEC guidance as to "participating affiliate" arrangements. These associated persons may, on behalf of the Manager, provide discretionary investment management services, trading, research and related services directly or indirectly to the Fund.

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**Purchase and redemption of** **Fund shares**

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 intermediary; through the Fund's website at nomuraassetmanagement.com/account-access; by calling 800 523-1918; by regular mail (c/o Nomura Funds, P.O. Box 534437, Pittsburgh, PA 15253-4437); by overnight courier service (c/o Nomura Funds Service Center, Attention: 534437, 500 Ross Street, 154-0520, Pittsburgh, PA 15262); or by wire.

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 Class R, Institutional Class, and Class R6 shares (except those shares purchased through an automatic investment plan), there is no minimum initial purchase requirement, but certain eligibility requirements must be met. The eligibility requirements are described in this 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.

Please refer to the "About your account" section of the Fund's Prospectus for more details regarding the purchase and sale of Fund shares.

**Tax information**

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-advantaged arrangement, such as a 401(k) plan or an IRA, in which case your distributions may be taxed as ordinary income when withdrawn from the tax-advantaged account.

**Payments to broker/dealers and other financial intermediaries**

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.

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**SMPR-189 2/26**<br>