# EDGAR Filing Document

**Accession Number:** 0001139819
**File Stem:** 0000930413-25-003537
**Filing Date:** 2025-11
**Character Count:** 39383
**Document Hash:** 5af975fb80f6dcc4e65c0533574a6905
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000930413-25-003537.hdr.sgml**: 20251126

**ACCESSION NUMBER**: 0000930413-25-003537

**CONFORMED SUBMISSION TYPE**: 497K

**PUBLIC DOCUMENT COUNT**: 5

**FILED AS OF DATE**: 20251126

**DATE AS OF CHANGE**: 20251126

**EFFECTIVENESS DATE**: 20251126

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** LORD ABBETT TRUST I
- **CENTRAL INDEX KEY:** 0001139819

**ORGANIZATION NAME:**
- **EIN:** 223805271
- **FISCAL YEAR END:** 0731

**FILING VALUES:**
- **FORM TYPE:** 497K
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-60304
- **FILM NUMBER:** 251530841

**BUSINESS ADDRESS:**
- **STREET 1:** 30 HUDSON STREET
- **CITY:** JERSEY CITY
- **STATE:** NJ
- **ZIP:** 07302
- **BUSINESS PHONE:** 201-827-2000

**MAIL ADDRESS:**
- **STREET 1:** 30 HUDSON STREET
- **CITY:** JERSEY CITY
- **STATE:** NJ
- **ZIP:** 07302

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** LORD ABBETT EQUITY TRUST
- **DATE OF NAME CHANGE:** 20110729

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** LORD ABBETT BLEND TRUST
- **DATE OF NAME CHANGE:** 20010502

## Series and Classes Contracts Data

### Lord Abbett Investment Grade Floating Rate Fund (Series ID: S000080204)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000241940 | Class R6     | LGRUX           |
| C000241941 | Class R5     | IGRSX           |
| C000241942 | Class R4     |  |
| C000241943 | Class R3     |  |
| C000241944 | Class A      | LGRAX           |
| C000241945 | Class I      | LGRYX           |
| C000241946 | Class F3     | IGRNX           |
| C000241947 | Class F      | LGRFX           |
| C000241948 | Class C      | IGRCX           |
| C000241949 | Class R2     |  |

![](img_22622750118b4.jpg)

SUMMARY PROSPECTUS

Lord Abbett Investment Grade Floating Rate Fund

DECEMBER 1, 2025

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| | | | | | |
|:---|:---|:---|:---|:---|:---|
| **CLASS/TICKER** | **CLASS/TICKER** | **CLASS/TICKER** | **CLASS/TICKER** | **CLASS/TICKER** | **CLASS/TICKER** |
| CLASS A  | LGRAX | CLASS I  | LGRFX | CLASS R5  | IGRSX |
| CLASS C  | IGRCX | CLASS R2  | N/A | CLASS R6  | LGRUX |
| CLASS F  | LGRFX | CLASS R3  | N/A |  |  |
| CLASS F3  | IGRNX | CLASS R4  | N/A |  |  |

---

Before you invest, you may want to review the Fund's prospectus and statement of additional information, which contain more information about the Fund and its risks. You can find the Fund's prospectus, statement of additional information and other information about the Fund at www.lordabbett.com/documentsandliterature. You can also get this information at no cost by calling 888-522-2388 (Option #2) or by sending an email request to literature@lordabbett.com. The current prospectus and statement of additional information dated December 1, 2025 as may be supplemented from time to time, are incorporated by reference into this summary prospectus.

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#### INVESTMENT OBJECTIVE
The Fund's investment objective is to seek a high level of current income.

#### FEES AND EXPENSES
This table 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 certain members of your family invest, or agree to invest in the future, at least $100,000 in the Lord Abbett Family of Funds. More information about these and other discounts is available from your financial intermediary and in "Sales Charge Reductions and Waivers" on page 64 of the prospectus, Appendix A to the prospectus, titled "Intermediary-Specific Sales Charge Reductions and Waivers," and "Purchases, Redemptions, Pricing, and Payments to Dealers" on page 9-1 of Part II of the statement of additional information ("SAI").

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Shareholder Fees<sup>(1)</sup>** | *(Fees paid directly from your investment)* | *(Fees paid directly from your investment)* | *(Fees paid directly from your investment)* | *(Fees paid directly from your investment)* |
| **Class** |  | **A** | **C** | **F, F3, I, R2, R3, R4, R5, and R6** |
| Maximum Sales Charge (Load) Imposed on Purchases <br>(as a percentage of offering price) | Maximum Sales Charge (Load) Imposed on Purchases <br>(as a percentage of offering price) | 2.25% |  |  |
| Maximum Deferred Sales Charge (Load) <br>(as a percentage of offering price or redemption <br>proceeds, whichever is lower) | Maximum Deferred Sales Charge (Load) <br>(as a percentage of offering price or redemption <br>proceeds, whichever is lower) | None<sup>(2)</sup> | 1.00%<sup>(3)</sup> |  |

---

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| | | | | | |
|:---|:---|:---|:---|:---|:---|
| **Annual Fund Operating Expenses** | **Annual Fund Operating Expenses** | **Annual Fund Operating Expenses** | **Annual Fund Operating Expenses** | **Annual Fund Operating Expenses** | **Annual Fund Operating Expenses** |
| *(Expenses that you pay each year as a percentage of the value of your investment)* | *(Expenses that you pay each year as a percentage of the value of your investment)* | *(Expenses that you pay each year as a percentage of the value of your investment)* | *(Expenses that you pay each year as a percentage of the value of your investment)* | *(Expenses that you pay each year as a percentage of the value of your investment)* | *(Expenses that you pay each year as a percentage of the value of your investment)* |
| **Class** | **A** | **&nbsp;&nbsp;&nbsp;&nbsp;C** | **F** | **F3** | **I** |
| Management Fees | 0.23% | 0.23% | 0.23% | 0.23% | 0.23% |
| Distribution and Service (12b-1) Fees | 0.20% | 0.94%<sup>(4)</sup> | 0.10% |  |  |
| Other Expenses | 0.14% | 0.14% | 0.14% | 0.08% | 0.14% |
| Total Annual Fund Operating Expenses<sup>(5)</sup> | 0.57% | 1.31% | 0.47% | 0.31% | 0.37% |

---

SUMMARY – Investment Grade Floating Rate Fund

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---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
| **Annual Fund Operating Expenses *(continued)*** | **Annual Fund Operating Expenses *(continued)*** | **Annual Fund Operating Expenses *(continued)*** | **Annual Fund Operating Expenses *(continued)*** | **Annual Fund Operating Expenses *(continued)*** | **Annual Fund Operating Expenses *(continued)*** |
| *(Expenses that you pay each year as a percentage of the value of your investment)* | *(Expenses that you pay each year as a percentage of the value of your investment)* | *(Expenses that you pay each year as a percentage of the value of your investment)* | *(Expenses that you pay each year as a percentage of the value of your investment)* | *(Expenses that you pay each year as a percentage of the value of your investment)* | *(Expenses that you pay each year as a percentage of the value of your investment)* |
| **Class** | **R2** | **R3** | **R4** | **R5** | **R6** |
| Management Fees | 0.23% | 0.23% | 0.23% | 0.23% | 0.23% |
| Distribution and Service (12b-1) Fees | 0.60% | 0.50% | 0.25% |  |  |
| Other Expenses | 0.14% | 0.14% | 0.14% | 0.14% | 0.08% |
| Total Annual Fund Operating Expenses<sup>(5)</sup> | 0.97% | 0.87% | 0.62% | 0.37% | 0.31% |

---

<sup>(1)</sup> A shareholder transacting in share classes without a front-end sales charge may be required to pay a commission to its financial intermediary. Please contact your financial intermediary for more information about whether such a commission may apply to your transaction.

<sup>(2)</sup> A contingent deferred sales charge ("CDSC") of 1.00% may be assessed on certain Class A shares purchased or acquired without a sales charge if they are redeemed before the first day of the month in which the one-year anniversary of the purchase falls.

<sup>(3)</sup> A CDSC of 1.00% may be assessed on Class C shares if they are redeemed before the first anniversary of their purchase. 

<sup>(4)</sup> The 12b-1 fee the Fund will pay on Class C shares will be a blended rate calculated based on (i) 1.00% of the Fund's average daily net assets attributable to shares held for less than one year and (ii) 0.80% of the Fund's average daily net assets attributable to shares held for one year or more. All Class C shareholders of the Fund will bear 12b-1 fees at the same rate.

<sup>(5)</sup> These amounts have been updated to reflect current fees and expenses.

#### 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. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same, giving effect to the fee waiver and expense reimbursement arrangement described above. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

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| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| **Class**  | **If Shares Are Redeemed** | **If Shares Are Redeemed** | **If Shares Are Redeemed** | **If Shares Are Redeemed** | **If Shares Are Not Redeemed** | **If Shares Are Not Redeemed** | **If Shares Are Not Redeemed** | **If Shares Are Not Redeemed** |
|  | **1 Year** | **3 Years** | **5 Years** | **10 Years** | **1 Year** | **3 Years** | **5 Years** | **10 Years** |
| Class A Shares  | $282 | $404 | $536 | $923 | $282 | $404 | $536 | $923 |
| Class C Shares  | $233 | $415 | $718 | $1375 | $133 | $415 | $718 | $1375 |
| Class F Shares  | $48 | $151 | $263 | $591 | $48 | $151 | $263 | $591 |
| Class F3 Shares  | $32 | $100 | $174 | $393 | $32 | $100 | $174 | $393 |
| Class I Shares  | $38 | $119 | $208 | $468 | $38 | $119 | $208 | $468 |
| Class R2 Shares  | $99 | $309 | $536 | $1190 | $99 | $309 | $536 | $1190 |
| Class R3 Shares  | $89 | $278 | $482 | $1073 | $89 | $278 | $482 | $1073 |
| Class R4 Shares  | $63 | $199 | $346 | $774 | $63 | $199 | $346 | $774 |
| Class R5 Shares  | $38 | $119 | $208 | $468 | $38 | $119 | $208 | $468 |
| Class R6 Shares  | $32 | $100 | $174 | $393 | $32 | $100 | $174 | $393 |

---

SUMMARY – Investment Grade Floating Rate Fund

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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 119% of the average value of its portfolio.

#### PRINCIPAL INVESTMENT STRATEGIES
The Fund will invest in various types of high quality, investment grade debt (or fixed income) securities. Under normal conditions, the Fund will pursue its investment objective by investing at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in floating or adjustable rate instruments and derivatives and other instruments that effectively enable the Fund to achieve a floating rate of income. In addition, under normal conditions, the Fund will invest at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in investment grade debt securities. Investment grade debt securities are securities that are rated within the four highest grades (at the time of purchase) assigned by a nationally recognized statistical rating organization such as Moody's Investors Service, Inc. (Aaa, Aa, A, Baa), S&P Global Ratings (AAA, AA, A, BBB), or Fitch Ratings (AAA, AA, A, BBB), or are unrated but determined by Lord Abbett to be of comparable quality.

The floating or adjustable rate instruments in which the Fund may invest include, but are not limited to:

&nbsp;&nbsp;&nbsp;&nbsp;· floating rate corporate debt securities of U.S. issuers;

&nbsp;&nbsp;&nbsp;&nbsp;· floating rate corporate debt securities of non-U.S. (including emerging market) issuers;

&nbsp;&nbsp;&nbsp;&nbsp;· securities issued or guaranteed by the U.S. Government, its agencies and instrumentalities;

&nbsp;&nbsp;&nbsp;&nbsp;· senior secured or unsecured floating rate loans or debt;

&nbsp;&nbsp;&nbsp;&nbsp;· floating-rate structured (or securitized) products and other hybrid instruments, including, but not limited to, U.S. and non-U.S. instruments and collateralized loan obligations; and

&nbsp;&nbsp;&nbsp;&nbsp;· mortgage-backed, mortgage-related, and other asset-backed securities, including privately issued mortgage-related securities and commercial mortgage-backed securities.

The other instruments that effectively enable the Fund to achieve a floating rate of income may include, but are not limited to:

SUMMARY – Investment Grade Floating Rate Fund

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&nbsp;&nbsp;&nbsp;&nbsp;· fixed-rate loans or debt with respect to which the Fund has entered into derivative instruments to effectively convert the fixed-rate interest payments into floating or adjustable rate interest payments; and

&nbsp;&nbsp;&nbsp;&nbsp;· money market investment companies.

The Fund seeks to manage interest rate risk through its management of the average duration of the securities in its portfolio.

The Fund may invest up to 20% of its net assets in securities rated below investment grade, including in high-yield debt securities (commonly referred to as "lower-rated" or "junk" bonds).

The Fund may invest in non-U.S. dollar-denominated loans or securities and in loans and securities issued by issuers organized in a country outside of the U.S. or economically tied to a country outside of the U.S., including in emerging markets.

The Fund invests in derivative instruments. Currently, the Fund expects to invest in derivatives consisting principally of futures, forwards, options, and swaps. The Fund may use derivatives to effectively convert the fixed-rate interest payments of a debt security held by the Fund into floating or adjustable rate interest payments; as a substitute for holding the underlying asset on which the derivative instrument is based; for cash management purposes; to manage portfolio duration; to attempt to hedge elements of its investment risk, on both a security- or portfolio-level basis; and to seek to enhance returns.

The portfolio management team buys, holds and sells securities using a relative value-oriented investment process, meaning the portfolio management team generally seeks more investment exposure to securities it believes to be undervalued and less investment exposure to securities it believes to be overvalued. The portfolio management team combines top-down and bottom-up analysis to construct its portfolio, using a blend of quantitative and fundamental research. As part of its top-down analysis, the portfolio management team evaluates global economic conditions, including monetary, fiscal, and regulatory policy, as well as the political and geopolitical environment, in order to identify and assess opportunities and risks across different segments of the fixed income market. The portfolio management team employs bottom-up analysis to identify and select securities for investment by the Fund based on in-depth company, industry, and market research and analysis. The portfolio management team may actively rotate sector exposure based on its assessment of relative value. The Fund may engage in active and frequent trading of its portfolio securities.

The Fund may sell a security when the Fund believes the security is less likely to benefit from the current market and economic environment, or shows signs of deteriorating fundamentals, among other reasons. The Fund may deviate from the investment strategy described above for temporary defensive purposes. The Fund may miss certain investment opportunities if defensive strategies are used and thus may not achieve its investment objective.

SUMMARY – Investment Grade Floating Rate Fund

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#### PRINCIPAL RISKS
As with any investment in a mutual fund, investing in the Fund involves risk, including the risk that you may receive little or no return on your investment. When you redeem your shares, they may be worth more or less than what you paid for them, which means that you may lose a portion or all of the money you invested in the Fund. The principal risks of investing in the Fund, which could adversely affect its performance, include:

&nbsp;&nbsp;&nbsp;&nbsp;· **Market Risk:** The market values of securities will fluctuate, sometimes sharply and unpredictably, based on overall economic conditions, governmental actions or intervention, market disruptions caused by trade disputes, tariffs or other factors, political developments, and other factors. Prices of equity securities tend to rise and fall more dramatically than those of debt securities.

&nbsp;&nbsp;&nbsp;&nbsp;· **Credit Risk:** Debt securities are subject to the risk that the issuer or guarantor of a security may not make interest and principal payments as they become due or may default altogether. In addition, if the market perceives a deterioration in the creditworthiness of an issuer, the value and liquidity of securities issued by that issuer may decline. To the extent that the Fund holds below investment grade securities, these risks may be heightened. Insured debt securities have the credit risk of the insurer in addition to the credit risk of the underlying investment being insured.

&nbsp;&nbsp;&nbsp;&nbsp;· **Interest Rate Risk:** As interest rates rise, prices of bonds (including tax-exempt bonds) generally fall, typically causing the Fund's investments to lose value. Additionally, rising interest rates or lack of market participants may lead to decreased liquidity in fixed income markets. Interest rate changes generally have a more pronounced effect on the market value of fixed-rate instruments, such as corporate bonds, than they have on floating rate instruments, and typically have a greater effect on the price of fixed income securities with longer durations. A wide variety of market factors can cause interest rates to rise, including central bank monetary policy, rising inflation, and changes in general economic conditions.

&nbsp;&nbsp;&nbsp;&nbsp;· **Portfolio Management Risk:** If the strategies used and investments selected by the Fund's portfolio management team fail to produce the intended result, the Fund may suffer losses or underperform other funds with the same investment objective or strategies, even in a favorable market.

&nbsp;&nbsp;&nbsp;&nbsp;· **Loan Risk:** Investments in floating or adjustable rate loans are subject to increased credit and liquidity risks. Loan prices also may be adversely affected by supply-demand imbalances caused by conditions in the loan market or related markets. Below investment grade loans, like high-yield debt securities, or junk bonds, usually are more credit sensitive than interest rate sensitive, although the value of these instruments may be affected by interest rate swings in the overall fixed income market. Loans may be subject to structural

SUMMARY – Investment Grade Floating Rate Fund

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subordination and may be subordinated to other obligations of the borrower or its subsidiaries.

&nbsp;&nbsp;&nbsp;&nbsp;· **Liquidity/Redemption Risk:** The Fund may lose money when selling securities at inopportune times to fulfill shareholder redemption requests. The risk of loss may increase depending on the size and frequency of redemption requests, whether the redemption requests occur in times of overall market turmoil or declining prices, and whether the securities the Fund intends to sell have decreased in value or are illiquid. The Fund may be less able to sell illiquid securities at its desired time or price. It may be more difficult for the Fund to value its investments in illiquid securities than more liquid securities.

&nbsp;&nbsp;&nbsp;&nbsp;· **Collateralized Loan Obligations and Other Collateralized Obligations Risk:** An investment in a collateralized loan obligation ("CLO") can be viewed as investing in (or through) another investment adviser and is subject to the layering of fees associated with such an investment. The risks of investing in a CLO generally can be summarized as a combination of economic risks of the underlying loans combined with the risks associated with the CLO structure governing the priority of payments, and include interest rate risk, credit risk, liquidity risk, prepayment risk, and the risk of default of the underlying asset, among others.

&nbsp;&nbsp;&nbsp;&nbsp;· **New Fund Risk:** The Fund is recently organized. There can be no assurance that the Fund will reach or maintain a sufficient asset size to effectively implement its investment strategy. In addition, until the Fund achieves sufficient scale, a Fund shareholder may experience proportionally higher Fund expenses than would be experienced by shareholders of a fund with a larger asset base.

&nbsp;&nbsp;&nbsp;&nbsp;· **Commercial Mortgage-Backed Securities Risk:** Commercial mortgage-backed securities ("CMBS") include securities that reflect an interest in, and are secured by, mortgage loans on commercial real property. Many of the risks of investing in CMBS reflect the risks of investing in the real estate securing the underlying mortgage loans. These risks reflect the effects of local and other economic conditions on real estate markets, the ability of tenants to make loan payments, and the ability of a property to attract and retain tenants. The economic impacts of COVID-19 have created a unique challenge for real estate markets, with the transition to remote-working environments potentially negatively impacting the occupancy rates of commercial real estate. CMBS may be less liquid and exhibit greater price volatility than other types of mortgage- or asset-backed securities.

&nbsp;&nbsp;&nbsp;&nbsp;· **Mortgage-Related and Other Asset-Backed Securities Risk:** Mortgage-related securities, including CMBS and other privately issued mortgage-related securities, and other asset-backed securities may be particularly sensitive to changes in prevailing interest rates and economic conditions, including delinquencies and defaults. The prices of mortgage-related and other asset-backed securities, depending on their structure and the rate of payments, can be

SUMMARY – Investment Grade Floating Rate Fund

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volatile. They are subject to prepayment risk (higher than expected prepayment rates of mortgage obligations due to a fall in market interest rates) and extension risk (lower than expected prepayment rates of mortgage obligations due to a rise in market interest rates). These risks increase the Fund's overall interest rate risk. Some mortgage-related securities receive government or private support, but there is no assurance that such support will remain in place.

&nbsp;&nbsp;&nbsp;&nbsp;· **Derivatives Risk:** The risks associated with derivatives may be different from and greater than the risks associated with directly investing in securities and other investments. Derivatives may increase the Fund's volatility and reduce its returns. Derivatives may not perform as expected and the Fund may not realize the intended benefits. Whether the Fund's use of derivatives is successful may depend on, among other things, the portfolio managers' ability to correctly forecast market movements, company and industry valuation levels and trends, changes in foreign exchange and interest rates, and other factors. If the portfolio managers incorrectly forecast these and other factors, the Fund's performance could suffer. Derivatives are also subject to liquidity risk and the risk that the counterparty to a derivative transaction may fail to fulfill its contractual obligations under the derivative contract. In addition, given their complexity, derivatives are subject to the risk that improper or misunderstood documentation may expose the Fund to losses.

&nbsp;&nbsp;&nbsp;&nbsp;· **Fixed Income Securities Risk:** The Fund is subject to the general risks and considerations associated with investing in debt securities, including the risk that issuers will fail to make timely payments of principal or interest or default altogether. Lower-rated securities in which the Fund may invest may be more volatile and may decline more in price in response to negative issuer developments or general economic news due to their increased credit risk relative to other fixed-income investments. In addition, as interest rates rise, the Fund's investments typically will lose value. Fiscal, economic, monetary, or other governmental policies or measures have in the past—and may in the future—cause or exacerbate interest rate risks.

&nbsp;&nbsp;&nbsp;&nbsp;· **Foreign and Emerging Market Company Risk:** Investments in foreign companies and in U.S. companies with economic ties to foreign markets generally involve special risks. These companies may be more vulnerable to economic, political, and social instability and subject to less government supervision, lack of transparency, inadequate regulatory and accounting standards, and foreign taxes. Foreign company securities also include American Depositary Receipts ("ADRs"), which may be less liquid than the underlying shares in their primary trading market. Foreign securities also may subject the Fund's investments to changes in currency exchange rates. Emerging market securities generally are more volatile than other foreign securities, and are subject to greater liquidity, regulatory, and political risks. Investments in emerging markets may be considered speculative and generally are riskier than investments in more developed markets. Emerging markets are more likely to experience hyperinflation and currency devaluations. Securities of emerging

SUMMARY – Investment Grade Floating Rate Fund

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market companies may have far lower trading volumes and less liquidity than securities of issuers in developed markets. In certain emerging market countries, governments participate to a significant degree in their respective economies. Action by these governments could have a significant adverse effect on market prices of securities and payment of dividends. Companies with economic ties to emerging markets may be susceptible to the same risks as companies organized in emerging markets.

&nbsp;&nbsp;&nbsp;&nbsp;· **Foreign Currency Risk:** Investments in securities that are denominated or receiving revenues in foreign currencies are subject to the risk that those currencies will decline in value relative to the U.S. dollar, or, in the case of hedged positions, that the U.S. dollar will decline in value relative to the currency being hedged. Foreign currency exchange rates may fluctuate significantly over short periods of time.

&nbsp;&nbsp;&nbsp;&nbsp;· **High Yield Securities Risk:** High yield securities (commonly referred to as "junk" bonds) typically pay a higher yield than investment grade securities, but may have greater price fluctuations and have a higher risk of default than investment grade securities. The market for high yield securities may be less liquid due to such factors as interest rate sensitivity, negative perceptions of the junk bond markets generally, and less secondary market liquidity. This may make such securities more difficult to sell at an acceptable price, especially during periods of financial distress, increased market volatility, or significant market decline.

&nbsp;&nbsp;&nbsp;&nbsp;· **Government Securities Risk:** The Fund invests in securities issued or guaranteed by the U.S. Government or its agencies and instrumentalities (such as the Government National Mortgage Association ("Ginnie Mae"), the Federal National Mortgage Association ("Fannie Mae"), or the Federal Home Loan Mortgage Corporation ("Freddie Mac")). Different types of U.S. government securities are subject to different levels of credit risk, including the risk of default, depending on the nature of the particular government support for that security. Unlike Ginnie Mae securities, securities issued or guaranteed by U.S. Government-related organizations, such as Fannie Mae and Freddie Mac, are not backed by the full faith and credit of the U.S. Government and no assurance can be given that the U.S. Government would provide financial support. Past long-term U.S. credit rating downgrades have introduced greater uncertainty about the ability of the United States to repay its obligations. The value of the Fund's shares may be adversely affected by any future rating agency downgrades.

&nbsp;&nbsp;&nbsp;&nbsp;· **High Portfolio Turnover Risk:** High portfolio turnover may result in increased transaction costs, reduced investment performance, and higher taxes resulting from increased realized capital gains, including short-term capital gains taxable as ordinary income when distributed to shareholders.

SUMMARY – Investment Grade Floating Rate Fund

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An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. For more information on the principal risks of the Fund, please see the "More Information About the Funds – Principal Risks" section in the prospectus.

#### PERFORMANCE
The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns. Each assumes reinvestment of dividends and distributions. The Fund's past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. No performance is shown for Class R2, R3, and R4 shares because the Fund has no Class R2, R3, and R4 shares outstanding.

The bar chart shows changes in the performance of the Fund's Class A shares from calendar year to calendar year. This chart does not reflect the sales charge applicable to Class A shares. If the sales charge were reflected, returns would be lower. Performance for the Fund's other share classes will vary due to the different expenses each class bears. Updated performance information is available at www.lordabbett.com or by calling 888-522-2388.

&nbsp;&nbsp;&nbsp;**Bar Chart (per calendar year) - Class A Shares\***<br>![PerformanceBarChartData(24:8.28)](img_c27b312149934.jpg)<br>**Best Quarter** 1st Q 2024 **+2.45% Worst Quarter** 4th Q 2024 **+1.72%**<br>*\* The total return for the Fund's Class A shares for the nine-month period from January 1, 2025 to September 30, 2025 was* <br>*4.50%.*<br>

The table below shows how the Fund's average annual total returns compare to the returns of a securities market index with investment characteristics similar to those of the Fund as well as to a broad-based securities market index.<sup>1</sup> The Fund's average annual total returns include applicable sales charges.

SUMMARY – Investment Grade Floating Rate Fund

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The after-tax returns of Class A shares included in the table below are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. In some cases, the return after taxes on distributions and sale of Fund shares may exceed the return before taxes due to a tax benefit resulting from realized losses on a sale of Fund shares at the end of the period that is used to offset other gains. Actual after-tax returns depend on an investor's tax situation and may differ from those shown. The after-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements such as 401(k) plans or Individual Retirement Accounts ("IRAs"). After-tax returns for other share classes are not shown in the table and will vary from those shown for Class A shares.

<sup>1</sup>The Fund has adopted the Bloomberg U.S. Aggregate Bond Index as its broad-based securities market index.

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| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** | **Average Annual Total Returns** | **Average Annual Total Returns** | **Average Annual Total Returns** |
| **(for the periods ended December 31, 2024)** | **(for the periods ended December 31, 2024)** | **(for the periods ended December 31, 2024)** | **(for the periods ended December 31, 2024)** |
| **Class** | **1 Year** | **Life of Class** | **Inception <br>Date for <br>Performance** |
| Class A Shares |  |  | 5/4/2023 |
| Before Taxes | 5.88% | 7.24% |  |
| After Taxes on Distributions | 3.08% | 4.33% |  |
| After Taxes on Distributions and Sale of Fund Shares | 3.42% | 4.28% |  |
| Class C Shares<sup>(1)</sup> | 6.47% | 7.88% | 5/4/2023 |
| Class F Shares | 8.50% | 8.93% | 5/4/2023 |
| Class F3 Shares | 8.56% | 9.00% | 5/4/2023 |
| Class I Shares | 8.50% | 8.93% | 5/4/2023 |
| Class R5 Shares | 8.49% | 8.93% | 5/4/2023 |
| Class R6 Shares | 8.56% | 9.00% | 5/4/2023 |
| **Index** |  |  |  |
| Bloomberg U.S. Floating Rate Notes | 6.42% | 6.59% | 5/4/2023 |
| *(reflects no deduction for fees, expenses, or taxes)* | 6.42% | 6.59% | 5/4/2023 |
| Bloomberg U.S. Aggregate Bond Index | 1.25% | 1.73% | 5/4/2023 |
| *(reflects no deduction for fees, expenses, or taxes)* | 1.25% | 1.73% | 5/4/2023 |

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<br> <sup>(1)</sup> Class C shares convert to Class A shares eight years after purchase. Class C share performance does not reflect the impact of such conversion to Class A shares.

#### MANAGEMENT
**Investment Adviser.** The Fund's investment adviser is Lord Abbett.

SUMMARY – Investment Grade Floating Rate Fund

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#### Portfolio Managers

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| | |
|:---|:---|
| **Portfolio Managers/Title** | **Member of<br>the Portfolio<br>Management<br>Team Since** |
| Adam C. Castle, Partner and Portfolio Manager | 2023 |
| Yoana N. Koleva, Partner and Portfolio Manager | 2023 |
| Harris A. Trifon, Partner and Portfolio Manager | 2023 |
| Robert A. Lee, Partner and Co-Head of Taxable Fixed Income | 2023 |
| Devin J. Hagens, Managing Director and Portfolio Manager | 2025 |

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#### PURCHASE AND SALE OF FUND SHARES
The minimum initial and additional amounts shown below vary depending on the class of shares you buy and the type of account. Certain financial intermediaries may impose different restrictions than those described below. For Class I shares, the minimum investment shown below applies to certain types of institutional investors, but does not apply to registered investment advisers or retirement and benefit plans otherwise eligible to invest in Class I shares. Class R2, R3, and R4 shares of the Fund are not currently offered. See "Choosing a Share Class – Investment Minimums" in the prospectus for more information.

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| | | | |
|:---|:---|:---|:---|
| **Investment Minimums — Initial/Additional Investments** | **Investment Minimums — Initial/Additional Investments** | **Investment Minimums — Initial/Additional Investments** | **Investment Minimums — Initial/Additional Investments** |
| **Class** | **A<sup>(1)</sup> and C** | **F, F3, R2, R3, R4, R5, and R6** | **I** |
| General and IRAs without Invest-A-Matic Investments | Initial: $1,500<br>Additional: No minimum | N/A | Initial: $1 million<br>Additional: No minimum |
| Invest-A-Matic Accounts<sup>(2)</sup> | Initial: $250<br>Additional: $50 | N/A | N/A |
| IRAs, SIMPLE and SEP Accounts with Payroll Deductions | No minimum | N/A | N/A |
| Fee-Based Advisory Programs and Retirement and Benefit Plans | No minimum | No minimum | No minimum |
| <sup>(1)</sup> There is no investment minimum for Class A shares purchased by investors maintaining an account with a financial intermediary that has entered into an agreement with Lord Abbett Distributor to offer Class A shares through a load-waived network or platform, which may or may not charge transaction fees.<br><sup>(2)</sup> There is no minimum initial investment for Invest-A-Matic accounts held directly with the Fund, including Individual Retirement Accounts ("IRAs"). | <sup>(1)</sup> There is no investment minimum for Class A shares purchased by investors maintaining an account with a financial intermediary that has entered into an agreement with Lord Abbett Distributor to offer Class A shares through a load-waived network or platform, which may or may not charge transaction fees.<br><sup>(2)</sup> There is no minimum initial investment for Invest-A-Matic accounts held directly with the Fund, including Individual Retirement Accounts ("IRAs"). | <sup>(1)</sup> There is no investment minimum for Class A shares purchased by investors maintaining an account with a financial intermediary that has entered into an agreement with Lord Abbett Distributor to offer Class A shares through a load-waived network or platform, which may or may not charge transaction fees.<br><sup>(2)</sup> There is no minimum initial investment for Invest-A-Matic accounts held directly with the Fund, including Individual Retirement Accounts ("IRAs"). | <sup>(1)</sup> There is no investment minimum for Class A shares purchased by investors maintaining an account with a financial intermediary that has entered into an agreement with Lord Abbett Distributor to offer Class A shares through a load-waived network or platform, which may or may not charge transaction fees.<br><sup>(2)</sup> There is no minimum initial investment for Invest-A-Matic accounts held directly with the Fund, including Individual Retirement Accounts ("IRAs"). |

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You may sell (redeem) shares through your securities broker, financial professional or financial intermediary on any business day the Fund calculates its NAV. If you have direct account access privileges, you may redeem your shares by contacting the Fund in writing at Lord Abbett Funds Service Center, P.O. Box 534489, Pittsburgh, PA 15253-4489 (regular mail) or Attention: 534489, 500 Ross Street 154-0520,

SUMMARY – Investment Grade Floating Rate Fund

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Pittsburgh, PA 15262 (overnight mail), by calling 888-522-2388 or by accessing your account online at www.lordabbett.com.

#### TAX INFORMATION
The Fund's distributions, if any, generally are taxable to you as ordinary income, capital gains or a combination of the two, unless you are a tax-exempt investor or investing through a tax-advantaged arrangement, such as a 401(k) plan or an IRA. Any withdrawals from such a tax-advantaged arrangement may be taxable to you.

#### PAYMENTS TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIES
If you purchase Fund shares through a broker-dealer or other financial intermediary (such as a bank), the Fund and the Fund's distributor or its affiliates 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 financial intermediary and your individual financial professional to recommend the Fund over another investment. Ask your individual financial professional or visit your financial intermediary's website for more information.

SUMMARY – Investment Grade Floating Rate Fund

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**NOTES:**<br>

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| | | |
|:---|:---|:---|
| **Investment Company Act File Number:** 811-10371 | ![](img_7a86d88d7e8c4.jpg) | ![](img_7a86d88d7e8c4.jpg) |
| ![](img_d7ecc2c690e14.jpg) | ![](img_d7ecc2c690e14.jpg) | **IGFR-7SUM<br>(12/25)** |

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