# EDGAR Filing Document

**Accession Number:** 0000887194
**File Stem:** 0000930413-26-000885
**Filing Date:** 2026-3
**Character Count:** 32117
**Document Hash:** e007d35df32ecabc0edf6b7b1eb191f2
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000930413-26-000885.hdr.sgml**: 20260326

**ACCESSION NUMBER**: 0000930413-26-000885

**CONFORMED SUBMISSION TYPE**: 497K

**PUBLIC DOCUMENT COUNT**: 5

**FILED AS OF DATE**: 20260326

**DATE AS OF CHANGE**: 20260326

**EFFECTIVENESS DATE**: 20260326

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** LORD ABBETT RESEARCH FUND INC
- **CENTRAL INDEX KEY:** 0000887194

**ORGANIZATION NAME:**
- **EIN:** 136995863
- **STATE OF INCORPORATION:** MD
- **FISCAL YEAR END:** 1130

**FILING VALUES:**
- **FORM TYPE:** 497K
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 033-47641
- **FILM NUMBER:** 26797398

**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 Growth Opportunities Fund (Series ID: S000006999)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000019093 | Class A      | LMGAX           |
| C000019095 | Class C      | LMGCX           |
| C000019096 | Class P      | LGOPX           |
| C000019097 | Class I      | LMGYX           |
| C000054715 | Class F      | LGOFX           |
| C000054716 | Class R2     | LGOQX           |
| C000054717 | Class R3     | LGORX           |
| C000156656 | Class R4     | LGOSX           |
| C000156657 | Class R5     | LGOTX           |
| C000156658 | Class R6     | LGOVX           |
| C000188282 | Class F3     | LOMGX           |

![](img_ed194d334cf84.jpg)

SUMMARY PROSPECTUS

Lord Abbett Growth Opportunities Fund

April 1, 2026

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| | | | | | |
|:---|:---|:---|:---|:---|:---|
| **CLASS/TICKER** | **CLASS/TICKER** | **CLASS/TICKER** | **CLASS/TICKER** | **CLASS/TICKER** | **CLASS/TICKER** |
| CLASS A  | LMGAX | CLASS I  | LMGYX | CLASS R4  | LGOSX |
| CLASS C  | LMGCX | CLASS P  | LGOPX | CLASS R5  | LGOTX |
| CLASS F  | LGOFX | CLASS R2  | LGOQX | CLASS R6  | LGOVX |
| CLASS F3  | LOMGX | CLASS R3  | LGORX |  |  |

---

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 investment objective is capital appreciation.

#### 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 $50,000 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 61 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, P, 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) | 5.75% |  |  |
| 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> |  |

---

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
| **Annual Fund Operating Expenses** | **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)* | *(Expenses that you pay each year as a percentage of the value of your investment)* |
| **Class** | **A** | **&nbsp;&nbsp;&nbsp;&nbsp;C** | **F** | **F3** | **&nbsp;&nbsp;&nbsp;&nbsp;I** | **&nbsp;&nbsp;&nbsp;&nbsp;P** |
| Management Fees | 0.65% | 0.65% | 0.65% | 0.65% | 0.65% | 0.65% |
| Distribution and Service (12b-1) Fees | 0.25% | 1.00% | 0.10% |  |  | 0.45% |
| Other Expenses | 0.21% | 0.21% | 0.21% | 0.12% | 0.21% | 0.21% |
| Total Annual Fund Operating Expenses | 1.11% | 1.86% | 0.96% | 0.77% | 0.86% | 1.31% |
| Fee Waiver and/or Expense Reimbursement<sup>(4)</sup> | (0.15)% | (0.15)% | (0.15)% | (0.15)% | (0.15)% | (0.15)% |
| Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement<sup>(4)</sup> | 0.96% | 1.71% | 0.81% | 0.62%<sup>(5)</sup> | 0.71% | 1.16% |

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SUMMARY – Growth Opportunities 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 | 0.65% | 0.65% | 0.65% | 0.65% | 0.65% |
| Distribution and Service (12b-1) Fees | 0.60% | 0.50% | 0.25% |  |  |
| Other Expenses | 0.21% | 0.21% | 0.21% | 0.21% | 0.12% |
| Total Annual Fund Operating Expenses | 1.46% | 1.36% | 1.11% | 0.86%<sup>(5)</sup> | 0.77% |
| Fee Waiver and/or Expense Reimbursement<sup>(4)</sup> | (0.15)% | (0.15)% | (0.15)% | (0.15)% | (0.15)% |
| Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement<sup>(4)</sup> | 1.31% | 1.21% | 0.96% | 0.71% | 0.62%<sup>(5)</sup> |

---

<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> For the period from April 1, 2026 through March 31, 2027, Lord, Abbett & Co. LLC ("Lord Abbett") has contractually agreed to waive its fees and reimburse expenses to the extent necessary to limit total net annual operating expenses, excluding any applicable 12b-1 fees, acquired fund fees and expenses, interest-related expenses, taxes, expenses related to litigation and potential litigation, and extraordinary expenses, to an annual rate of 0.62% for each of Class F3 and R6 shares and to an annual rate of 0.71% for each other class. This agreement may be terminated only by the Fund's Board of Directors.

<sup>(5)</sup> These amounts have been updated from fiscal year amounts 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. 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:

SUMMARY – Growth Opportunities Fund

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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  | $667 | $894 | $1138 | $1836 | $667 | $894 | $1138 | $1836 |
| Class C Shares  | $274 | $570 | $992 | $1971 | $174 | $570 | $992 | $1971 |
| Class F Shares  | $83 | $291 | $516 | $1164 | $83 | $291 | $516 | $1164 |
| Class F3 Shares  | $63 | $231 | $413 | $940 | $63 | $231 | $413 | $940 |
| Class I Shares  | $73 | $259 | $462 | $1047 | $73 | $259 | $462 | $1047 |
| Class P Shares  | $118 | $400 | $704 | $1566 | $118 | $400 | $704 | $1566 |
| Class R2 Shares  | $133 | $447 | $783 | $1733 | $133 | $447 | $783 | $1733 |
| Class R3 Shares  | $123 | $416 | $730 | $1622 | $123 | $416 | $730 | $1622 |
| Class R4 Shares  | $98 | $338 | $597 | $1338 | $98 | $338 | $597 | $1338 |
| Class R5 Shares  | $73 | $259 | $462 | $1047 | $73 | $259 | $462 | $1047 |
| Class R6 Shares  | $63 | $231 | $413 | $940 | $63 | $231 | $413 | $940 |

---

**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 100% of the average value of its portfolio.

#### PRINCIPAL INVESTMENT STRATEGIES
The Fund invests in equity securities of mid-sized companies that the portfolio management team believes demonstrate above-average, long-term growth potential. Under normal conditions, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in equity securities of mid-sized companies. A mid-sized company is defined as a company having a market capitalization at the time of purchase that falls within the market capitalization range of companies in the Russell Midcap<sup>®</sup> Index. The portfolio management team seeks to invest in the stocks of companies with strong business models, management, and competitive positions that are targeting markets that appear most likely to benefit from increased innovation. The team believes these companies possess revenue and earnings growth potential that can exceed market expectations.

Equity securities in which the Fund may invest include common stocks, preferred stocks, equity interests in trusts (including real estate investment trusts ("REITs") and privately offered trusts), partnerships, joint ventures, limited liability companies and vehicles with similar legal structures, other instruments convertible or exercisable into the foregoing, and other investments with similar economic characteristics.

The Fund may invest up to 20% of its net assets in securities of foreign companies, including emerging market companies, American Depositary Receipts ("ADRs"),

SUMMARY – Growth Opportunities Fund

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Global Depository Receipts ("GDRs"), and other similar depositary receipts. In addition to ADRs, the Fund generally defines foreign companies as those whose securities are traded primarily on non-U.S. securities exchanges.

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.** 

#### 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.

&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.

&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;· **Equity Securities Risk:** Equity securities, as well as equity-like securities such as convertible debt securities, may experience significant volatility. Such securities may fall sharply in response to adverse events affecting overall markets, a particular industry or sector, or an individual company's financial condition.

&nbsp;&nbsp;&nbsp;&nbsp;· **Industry and Sector Risk:** Although the Fund does not employ an industry or sector focus, its exposure to specific industries or sectors will increase from time to time based on the portfolio management team's perception of investment opportunities. If the Fund is overweight in a single industry or sector relative to its benchmark index, the Fund will face an increased risk that the value of its

SUMMARY – Growth Opportunities Fund

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portfolio will decrease because of events disproportionately affecting that industry or sector. Furthermore, investments in particular industries or sectors may be more volatile than the broader market as a whole.

&nbsp;&nbsp;&nbsp;&nbsp;· **Mid-Sized Company Risk:** Investments in mid-sized companies may involve greater risks than investments in larger, more established companies. Securities of mid-sized companies tend to be more sensitive to changing economic, market, and industry conditions and tend to be more volatile and less liquid than equity securities of larger companies, especially over the short term. The securities of mid-sized companies tend to trade less frequently than those of larger, more established companies, which can adversely affect the pricing of these securities and the ability to sell these securities in the future.

&nbsp;&nbsp;&nbsp;&nbsp;· **Growth Investing Risk:** Growth stocks typically trade at higher multiples of current earnings as compared to other stocks, which may lead to inflated prices. Growth stocks often are more sensitive to market fluctuations than other securities because their market prices are highly sensitive to future earnings expectations. At times when it appears that these expectations may not be met, prices of growth stocks typically fall. Growth stocks may be more volatile than securities of slower-growing issuers.

&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 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;· **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

SUMMARY – Growth Opportunities Fund

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currency being hedged. Foreign currency exchange rates may fluctuate significantly over short periods of time.

&nbsp;&nbsp;&nbsp;&nbsp;· **Real Estate Risk:** An investment in a REIT generally is subject to the risks that impact the value of the underlying properties or mortgages of the REIT. These risks include loss to casualty or condemnation, and changes in supply and demand, interest rates, zoning laws, regulatory limitations on rents, property taxes, and operating expenses. Other factors that may adversely affect REITs include poor performance by management of the REIT, changes to the tax laws, or failure by the REIT to qualify for favorable tax treatment under the Internal Revenue Code of 1986, as amended (the "Code"), and changes in local, regional, or general economic conditions.

&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.

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.

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.

SUMMARY – Growth Opportunities Fund

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&nbsp;&nbsp;&nbsp;**Bar Chart (per calendar year) - Class A Shares**<br>![PerformanceBarChartData(16:1.04,17:22.84,18:-3.36,19:36.75,20:40.06,21:6.61,22:-32.59,23:10.8,24:30.74,25:13.27)](img_868a2113c9bd4.jpg)<br>**Best Quarter** 2nd Q 2020 **+31.78% Worst Quarter** 1st Q 2020 **-19.38%**<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> 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 S&P 500<sup>®</sup> Index as its broad-based securities market index.

SUMMARY – Growth Opportunities Fund

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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 | 6.74% | 2.13% | 9.83% | - |  |
| After Taxes on Distributions | 4.94% | 0.93% | 8.16% | - |  |
| After Taxes on Distributions and Sale of Fund Shares | 5.26% | 1.52% | 7.65% | - |  |
| Class C Shares<sup>(1)</sup> | 11.44% | 2.58% | 9.65% | - |  |
| Class F Shares | 13.46% | 3.50% | 10.64% | - |  |
| Class F3 Shares | 13.68% | 3.70% | - | 11.55% | 4/4/2017 |
| Class I Shares | 13.57% | 3.61% | 10.76% | - |  |
| Class P Shares | 13.07% | 3.15% | 10.26% | - |  |
| Class R2 Shares | 12.86% | 2.99% | 10.10% | - |  |
| Class R3 Shares | 12.99% | 3.10% | 10.21% | - |  |
| Class R4 Shares | 13.27% | 3.36% | 10.48% | - |  |
| Class R5 Shares | 13.54% | 3.62% | 10.77% | - |  |
| Class R6 Shares | 13.69% | 3.70% | 10.85% | - |  |
| **Index** |  |  |  |  |  |
| Russell Midcap<sup>®</sup> Growth Index | 8.66% | 6.65% | 12.49% | 12.78% | 4/4/2017 |
| *(reflects no deduction for fees, expenses, or taxes)* | 8.66% | 6.65% | 12.49% | 12.78% | 4/4/2017 |
| Russell Midcap<sup>®</sup> Index | 10.60% | 8.67% | 11.01% | 10.49% | 4/4/2017 |
| *(reflects no deduction for fees, expenses, or taxes)* | 10.60% | 8.67% | 11.01% | 10.49% | 4/4/2017 |
| S&P 500<sup>®</sup> Index | 17.88% | 14.42% | 14.82% | 14.86% | 4/4/2017 |
| *(reflects no deduction for fees, expenses, or taxes)* | 17.88% | 14.42% | 14.82% | 14.86% | 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.

SUMMARY – Growth Opportunities Fund

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#### Portfolio Managers

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| | |
|:---|:---|
| **Portfolio Managers/Title** | **Member of<br>the Portfolio<br>Management<br>Team Since** |
| F. Thomas O'Halloran, Partner and Portfolio Manager | 2022 |
| Matthew R. DeCicco, Partner and Director of Equities | 2022 |
| Vernon T. Bice, Managing Director and Portfolio Manager | 2022 |
| Benjamin Ebel, Senior Managing Director and Portfolio Manager | 2022 |

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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 P shares are closed to substantially all new investors. 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, P, R2, R3, R4, R5, and R6** | **I** |
| General and IRAs without Invest-A-Matic Investments | Initial: $1,000<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.

SUMMARY – Growth Opportunities Fund

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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.

SUMMARY – Growth Opportunities Fund

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| **Investment Company Act File Number:** 811-06650 | ![](img_a732f017ba904.jpg) | ![](img_a732f017ba904.jpg) |
| ![](img_12661b6d0e094.jpg) | ![](img_12661b6d0e094.jpg) | **LAGOF-7SUM<br>(04/26)** |

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