# EDGAR Filing Document

**Accession Number:** 0000911507
**File Stem:** 0000930413-26-000920
**Filing Date:** 2026-3
**Character Count:** 45918
**Document Hash:** 110202dae2600fd052444b0c8ad043cc
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000930413-26-000920.hdr.sgml**: 20260327

**ACCESSION NUMBER**: 0000930413-26-000920

**CONFORMED SUBMISSION TYPE**: 497K

**PUBLIC DOCUMENT COUNT**: 5

**FILED AS OF DATE**: 20260327

**DATE AS OF CHANGE**: 20260327

**EFFECTIVENESS DATE**: 20260327

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** LORD ABBETT INVESTMENT TRUST
- **CENTRAL INDEX KEY:** 0000911507

**ORGANIZATION NAME:**
- **EIN:** 133731507
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1130

**FILING VALUES:**
- **FORM TYPE:** 497K
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 033-68090
- **FILM NUMBER:** 26805611

**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

## Series and Classes Contracts Data

### Lord Abbett Inflation Focused Fund (Series ID: S000031962)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000099493 | Class A      | LIFAX           |
| C000099494 | Class C      | LIFCX           |
| C000099495 | Class F      | LIFFX           |
| C000099496 | Class I      | LIFIX           |
| C000099497 | Class R2     | LIFQX           |
| C000099498 | Class R3     | LIFRX           |
| C000156650 | Class R4     | LIFKX           |
| C000156651 | Class R5     | LIFTX           |
| C000156652 | Class R6     | LIFVX           |
| C000188254 | Class F3     | LIFOX           |

![](img_53ae6d44fb4b4.jpg)

SUMMARY PROSPECTUS

Lord Abbett Inflation Focused Fund

APRIL 1, 2026

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| | | | | | |
|:---|:---|:---|:---|:---|:---|
| **CLASS/TICKER** | **CLASS/TICKER** | **CLASS/TICKER** | **CLASS/TICKER** | **CLASS/TICKER** | **CLASS/TICKER** |
| CLASS A  | LIFAX | CLASS I  | LIFIX | CLASS R5  | LIFTX |
| CLASS C  | LIFCX | CLASS R2  | LIFQX | CLASS R6  | LIFVX |
| CLASS F  | LIFFX | CLASS R3  | LIFRX |  |  |
| CLASS F3  | LIFOX | CLASS R4  | LIFKX |  |  |

---

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 April 1, 2026 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 primary investment objective is to provide investment returns that exceed the rate of inflation in the U.S. economy over a full economic cycle. As a secondary objective, the Fund seeks 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 292 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 | 0.30% | 0.30% | 0.30% | 0.30% | 0.30% |
| Distribution and Service (12b-1) Fees | 0.20% | 0.80%<sup>(4)</sup> | 0.10% |  |  |
| Other Expenses | 0.24% | 0.24% | 0.24% | 0.14% | 0.24% |
| Total Annual Fund Operating Expenses | 0.74% | 1.34% | 0.64% | 0.44% | 0.54% |

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SUMMARY – INFLATION FOCUSED 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 | 0.30% | 0.30% | 0.30% | 0.30% | 0.30% |
| Distribution and Service (12b-1) Fees | 0.60% | 0.50% | 0.25% |  |  |
| Other Expenses | 0.24% | 0.24% | 0.24% | 0.24% | 0.14% |
| Total Annual Fund Operating Expenses | 1.14% | 1.04% | 0.79% | 0.54% | 0.44% |

---

<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.

#### 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. Class C shares automatically convert to Class A shares after eight years. The expense example for Class C shares for the ten-year period reflects the conversion to Class A shares. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

---

| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| **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  | $299 | $456 | $627 | $1123 | $299 | $456 | $627 | $1123 |
| Class C Shares  | $236 | $425 | $734 | $1448 | $136 | $425 | $734 | $1448 |
| Class F Shares  | $65 | $205 | $357 | $798 | $65 | $205 | $357 | $798 |
| Class F3 Shares  | $45 | $141 | $246 | $555 | $45 | $141 | $246 | $555 |
| Class I Shares  | $55 | $173 | $302 | $677 | $55 | $173 | $302 | $677 |
| Class R2 Shares  | $116 | $362 | $628 | $1386 | $116 | $362 | $628 | $1386 |
| Class R3 Shares  | $106 | $331 | $574 | $1271 | $106 | $331 | $574 | $1271 |
| Class R4 Shares  | $81 | $252 | $439 | $978 | $81 | $252 | $439 | $978 |
| Class R5 Shares  | $55 | $173 | $302 | $677 | $55 | $173 | $302 | $677 |
| Class R6 Shares  | $45 | $141 | $246 | $555 | $45 | $141 | $246 | $555 |

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SUMMARY – INFLATION FOCUSED 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 175% of the average value of its portfolio.

#### PRINCIPAL INVESTMENT STRATEGIES
For purposes of its investment objective, the Fund uses the Consumer Price Index ("CPI") for All Urban Consumers ("CPI-U") to measure the rate of inflation in the U.S. economy. The Fund pursues its investment objective by combining inflation-linked derivatives and inflation-indexed fixed income securities (collectively, "Inflation-Linked Investments") with a portfolio of fixed income securities. In addition, the Fund may buy or sell Treasury futures or interest rate swaps to actively manage its portfolio duration. The use of the term "Inflation Focused" in the Fund's name does not refer to a particular type of security in which the Fund invests; rather, it refers to its overall strategy that seeks investment returns that exceed the rate of inflation in the U.S. economy over time. In the Fund's view, exceeding the rate of inflation in the U.S. economy could mean achieving greater gains than the CPI-U during periods of anticipated or actual inflation or sustaining smaller losses than the CPI-U during periods of anticipated or actual deflation.

The percentage of the Fund's assets that is invested in Inflation-Linked Investments and the types of Inflation-Linked Investments used by the Fund will vary. The Fund does not seek to forecast inflationary trends, but merely seeks investment exposure through Inflation-Linked Investments. Because the Fund uses Inflation-Linked Investments as a tool to gain investment exposure, the Fund is designed for long-term investors and may not be appropriate for investors who are looking to protect their purchasing power in the near term.

The specific types of Inflation-Linked Investments that the Fund may use include:

&nbsp;&nbsp;&nbsp;&nbsp;· **Inflation-Linked Derivatives:** The Fund may invest substantially in inflation-linked derivatives, primarily CPI swaps. A CPI swap is a contract in which one party agrees to pay a fixed rate in exchange for a variable rate, which is the rate of change in the CPI during the life of the contract. Payments are based on a specified notional amount of principal. The Fund normally may enter into CPI swaps on a zero-coupon basis, meaning that the floating rate will be based on the cumulative CPI during the life of the contract, and the fixed rate will compound until the swap's maturity date, at which point the payments are netted. Conversely, the Fund may enter into CPI swaps on a year-over-year basis, in which one party pays an annual fixed rate on a specified notional amount at specified intervals (*i.e.*, monthly, annually, etc.), while the other party pays the annual year-over-year inflation rate at specified intervals.

SUMMARY – INFLATION FOCUSED FUND

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The Fund may invest substantially in other types of derivatives for non-hedging or hedging purposes. Currently, the Fund expects to invest in derivatives consisting principally of futures, forwards, options, and swaps. For example, the Fund may invest in or sell short U.S. Treasury futures, securities index futures, other futures, and/or currency forwards to adjust the Fund's exposure to the direction of interest rates, or for other portfolio management reasons. The Fund is regulated by the Commodity Futures Trading Commission (the "CFTC") as a commodity pool.

&nbsp;&nbsp;&nbsp;&nbsp;· **Inflation-Indexed Fixed Income Securities:** Inflation-indexed fixed income securities are securities whose principal and/or interest payments are adjusted for inflation, unlike traditional fixed income securities that make fixed or variable principal and interest payments. The Fund may invest in Treasury Inflation Protected Securities ("TIPS"), which are U.S. Government bonds whose principal automatically is adjusted for inflation as measured by the CPI, and other inflation-indexed securities issued by the U.S. Department of the Treasury. In addition to investing in TIPS, the Fund also may invest in sovereign inflation-indexed fixed income securities (sometimes referred to as "linkers") issued by non-U.S. governments. To the extent that the Fund invests in such non-U.S. inflation-indexed fixed income securities that are denominated in foreign currencies, the Fund will limit such investments in accordance with the limitations described further below.

The Fund invests the remainder of its assets in fixed income securities of various types and will use such securities to cover its obligations under CPI swaps and other derivative transactions. The Fund may invest in fixed income securities with both fixed and variable interest rates. Among such fixed income securities in which the Fund may invest without limitation are investment grade:

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

&nbsp;&nbsp;&nbsp;&nbsp;· corporate debt securities of non-U.S. (including emerging market) issuers that are denominated in U.S. dollars;

&nbsp;&nbsp;&nbsp;&nbsp;· mortgage-backed, mortgage-related, and other asset-backed securities, including collateralized mortgage obligations ("CMOs"), commercial mortgage-backed securities ("CMBS"), mortgage dollar rolls, and stripped mortgage-backed securities ("SMBS"); and

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

The Fund may invest up to 35% of its net assets in any one or a combination of the following types of fixed income securities and other instruments:

&nbsp;&nbsp;&nbsp;&nbsp;· high-yield debt securities (commonly referred to as "lower-rated" or "junk" bonds);

SUMMARY – INFLATION FOCUSED FUND

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&nbsp;&nbsp;&nbsp;&nbsp;· debt securities of non-U.S. (including emerging market) issuers that are denominated in foreign currencies;

&nbsp;&nbsp;&nbsp;&nbsp;· loans, including bridge loans, novations, assignments, and participations;

&nbsp;&nbsp;&nbsp;&nbsp;· convertible securities, including convertible bonds and preferred stocks; and

&nbsp;&nbsp;&nbsp;&nbsp;· structured securities and other hybrid instruments, including collateralized loan obligations ("CLOs").

The Fund will not invest more than 25% of its total assets in any industry; however, this limitation does not apply to mortgage-backed securities, privately issued mortgage-related securities, or securities issued by the U.S. Government, its agencies and instrumentalities.

The Fund seeks to manage the average duration of the securities it holds in its portfolio and hedge interest rate risk by investing in Treasury futures and interest rate swaps. The duration of a security takes into account the pattern of all expected payments of interest and principal on the security over time, including how these payments are affected by changes in interest rates.

The portfolio management team combines top-down and bottom-up analysis in its portfolio construction process. The portfolio management team takes into account several factors in its analysis, including, but not limited to, current and expected economic conditions, rising and falling interest rates, and credit quality. The portfolio management team may actively rotate sector exposure based on its assessment of relative value. The Fund engages 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.

#### 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;· **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.

SUMMARY – INFLATION FOCUSED FUND

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&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;· **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;· **Inflation-Linked Investments Risk:** Unlike traditional fixed income securities, the principal and interest payments of inflation-linked investments are adjusted periodically based on the inflation rate. The value of the Fund's inflation-linked investments may be vulnerable to changes in expectations of inflation or interest rates and there is no guarantee that the Fund's use of these instruments will be successful.

&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;· **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

SUMMARY – INFLATION FOCUSED FUND

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during periods of financial distress, increased market volatility, or significant market decline.

&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;· **Counterparty Risk:** A significant risk in contracts such as CPI swaps, futures, options and other derivative transactions is the creditworthiness of the counterparty because the integrity of the transaction depends on the willingness and ability of the counterparty to meet its contractual obligations. If a counterparty fails to meet its contractual obligations, is subject to an insolvency proceeding, or otherwise experiences a business interruption, the Fund could, for example, be delayed in or prevented from obtaining payments owed to it or from realizing on collateral, miss investment opportunities or otherwise hold investments it would prefer to sell, resulting in losses for the Fund. Counterparty risk is heightened during unusually adverse market conditions. Also, under certain regulatory regimes, the Fund's ability to exercise remedies could be stayed or eliminated in the event of a counterparty's (or its affiliate's) insolvency. In particular, governmental authorities could reduce, eliminate, or convert to equity the liabilities to the Fund of a counterparty experiencing financial difficulties.

&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.

SUMMARY – INFLATION FOCUSED FUND

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&nbsp;&nbsp;&nbsp;&nbsp;· **Leverage Risk:** Certain of the Fund's transactions (including, among others, forward foreign currency contracts and other derivatives, reverse repurchase agreements, and the use of when-issued, delayed delivery or forward commitment transactions) may give rise to leverage risk. Leverage may increase volatility in the Fund by magnifying the effect of changes in the value of the Fund's holdings. The use of leverage may cause the Fund to lose more money in adverse environments than would have been the case in the absence of leverage. There is no assurance that the Fund will be able to employ leverage successfully.

&nbsp;&nbsp;&nbsp;&nbsp;· **Tax Treatment Limitations and Potential Changes in Tax Treatment Risk:** The Fund intends to continue to qualify as a "regulated investment company" under subchapter M of the Internal Revenue Code of 1986, as amended (the "Code"). In order to qualify as a regulated investment company under subchapter M, at least 90% of the Fund's gross income for each taxable year must be "qualifying income." Although the Fund believes that its investment strategies with respect to derivatives, including CPI swaps, will generate qualifying income under current U.S. federal income tax law, the Fund's use of these instruments is accompanied by the risk that the Internal Revenue Service may determine that such gain is non-qualifying income. The Fund's intention to qualify for favorable tax treatment under the Code may limit the Fund's ability to invest in certain investments, especially commodity related investments, which may offer the potential to hedge against inflation. In addition, the Fund's transactions in futures, swaps and other derivatives could also result in the Fund realizing more short-term capital gain and ordinary income (both subject to ordinary income tax rates when distributed to shareholders) than otherwise would be the case if the Fund did not invest in such instruments. To the extent that the Fund invests in this manner, the realization of short-term gain and ordinary income may impact the amount, timing, and character of the Fund's distributions to shareholders and the Fund's after-tax returns.

&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;· **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

SUMMARY – INFLATION FOCUSED FUND

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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 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;· **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;· **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 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;· **Commercial Mortgage-Backed Securities Risk:** CMBS include securities that reflect an interest in, and are secured by, mortgage loans on commercial real

SUMMARY – INFLATION FOCUSED FUND

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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;· **Convertible Securities Risk:** Convertible securities are subject to the risks affecting both equity and fixed income securities, including market, credit, liquidity, and interest rate risk. Convertible securities tend to be more volatile than other fixed income securities, and the markets for convertible securities may be less liquid than markets for common stocks or bonds. A significant portion of convertible securities have below investment grade credit ratings and are subject to increased credit and liquidity risks.

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

&nbsp;&nbsp;&nbsp;&nbsp;· **Collateralized Loan Obligations and Other Collateralized Obligations Risk:** An investment in a 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.

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.

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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(16:4.96,17:1.33,18:-1.28,19:4.86,20:5.93,21:10.29,22:-4.85,23:4.1,24:4.9,25:7.01)](img_a630ddbae3bb4.jpg)<br>**Best Quarter** 2nd Q 2020 **+10.55% Worst Quarter** 1st Q 2020 **-14.80%**<br>

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

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** | **Average Annual Total Returns** | **Average Annual Total Returns** |
| **(for the periods ended December 31, 2025)** | **(for the periods ended December 31, 2025)** | **(for the periods ended December 31, 2025)** | **(for the periods ended December 31, 2025)** | **(for the periods ended December 31, 2025)** | **(for the periods ended December 31, 2025)** |
| **Class** | **1 Year** | **5 Years** | **10 Years** | **Life of Class** | **Inception <br>Date for <br>Performance** |
| Class A Shares |  |  |  |  |  |
| Before Taxes | 4.57% | 3.69% | 3.41% | - |  |
| After Taxes on Distributions | 2.58% | 2.11% | 1.78% | - |  |
| After Taxes on Distributions and Sale of Fund Shares | 2.68% | 2.14% | 1.87% | - |  |
| Class C Shares<sup>(1)</sup> | 5.28% | 3.49% | 2.98% | - |  |
| Class F Shares | 7.11% | 4.28% | 3.76% | - |  |
| Class F3 Shares | 7.34% | 4.47% | - | 3.82% | 4/4/2017 |
| Class I Shares | 7.13% | 4.36% | 3.84% | - |  |
| Class R2 Shares | 6.60% | 3.69% | 3.19% | - |  |
| Class R3 Shares | 6.60% | 3.84% | 3.34% | - |  |
| Class R4 Shares | 6.87% | 4.10% | 3.58% | - |  |
| Class R5 Shares | 7.23% | 4.38% | 3.85% | - |  |
| Class R6 Shares | 7.34% | 4.44% | 3.95% | - |  |
| **Index** |  |  |  |  |  |
| Bloomberg U.S. 1-5 Year TIPS Index | 6.55% | 3.32% | 3.16% | 3.16% | 4/4/2017 |
| *(reflects no deduction for fees, expenses, or taxes)* | 6.55% | 3.32% | 3.16% | 3.16% | 4/4/2017 |
| Consumer Price Index for All Urban Consumers ("CPI-U") | 2.67% | 4.47% | 3.20% | 3.30% | 4/4/2017 |
| *(reflects no deduction for fees, expenses, or taxes)* | 2.67% | 4.47% | 3.20% | 3.30% | 4/4/2017 |
| ICE BofA 1–3 Year U.S. Corporate Index | 5.93% | 2.53% | 2.81% | 2.86% | 4/4/2017 |
| *(reflects no deduction for fees, expenses, or taxes)* | 5.93% | 2.53% | 2.81% | 2.86% | 4/4/2017 |
| Bloomberg U.S. Aggregate Bond Index | 7.30% | -0.36% | 2.01% | 1.87% | 4/4/2017 |
| *(reflects no deduction for fees, expenses, or taxes)* | 7.30% | -0.36% | 2.01% | 1.87% | 4/4/2017 |

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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 & Co. LLC ("Lord Abbett").

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#### Portfolio Managers

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| | |
|:---|:---|
| **Portfolio Managers/Title** | **Member of<br>the Portfolio<br>Management<br>Team Since** |
| Leah G. Traub, Partner and Portfolio Manager | 2021 |
| Robert A. Lee, Partner and Co-Head of Taxable Fixed Income | 2011 |
| Andrew H. O'Brien, Partner and Portfolio Manager | 2011 |
| Steven F. Rocco, Partner and Co-Head of Taxable Fixed Income | 2013 |

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

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#### 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.

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| | | |
|:---|:---|:---|
| **Investment Company Act File Number:** 811-07988 | ![](img_3cf9f3b23f9f4.jpg) | ![](img_3cf9f3b23f9f4.jpg) |
| ![](img_1df047ba1fa94.jpg) | ![](img_1df047ba1fa94.jpg) | **IFF-7SUM<br>(04/26)** |

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