micro_cap_growth_fund_summary

SUMMARY PROSPECTUS

Lord Abbett Micro Cap Growth Fund

MARCH 1, 2025

CLASS/TICKER

CLASS A ............

LAMGX

CLASS I...........

LMIYX

CLASS R5 .......

N/A

CLASS C............

LCMGX

CLASS R2 .......

N/A

CLASS R6 .......

N/A

CLASS F ............

LFMGX

CLASS R3 .......

N/A

CLASS F3 ..........

N/A

CLASS R4 .......

N/A

The Lord Abbett Micro Cap Growth Fund generally is not available for purchase by new

investors, except as described in the prospectus. Please see the section “Information about the

Availability of Micro Cap Growth Fund” for more information.

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 March 1, 2025 as may be

supplemented from time to time, are incorporated by reference into this summary prospectus.

SUMMARY – Micro Cap Growth Fund

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term 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 231 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

(1)

(Fees paid directly from your investment)

Class

F, F3, I, R2, R3, R4, R5, and R6

Maximum Sales Charge (Load) Imposed on Purchases

(as a percentage of offering price)

5.75%

None

Maximum Deferred Sales Charge (Load)

(as a percentage of offering price or redemption

proceeds, whichever is lower)

None

(2)

1.00%

(3)

None

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Class

Management Fees

0.90%

Distribution and Service (12b-1) Fees

0.25%

1.00%

0.10%

None

Other Expenses

0.23%

0.15%

0.23%

Total Annual Fund Operating Expenses

1.38%

2.13%

1.23%

1.05%

1.13%

Fee Waiver and/or Expense Reimbursement

None

(0.10)%

(4)

None

Total Annual Fund Operating Expenses After Fee Waiver

and/or Expense Reimbursement

1.38%

2.13%

1.13%

1.05%

1.13%

SUMMARY – Micro Cap Growth Fund

Annual Fund Operating Expenses

(continued)

(Expenses that you pay each year as a percentage of the value of your investment)

Class

Management Fees

0.90%

Distribution and Service (12b-1) Fees

0.60%

0.50%

0.25%

None

Other Expenses

0.23%

0.15%

Total Annual Fund Operating Expenses

1.73%

1.63%

1.38%

1.13%

1.05%

Fee Waiver and/or Expense Reimbursement

None

Total Annual Fund Operating Expenses After Fee Waiver and/or

Expense Reimbursement

1.73%

1.63%

1.38%

1.13%

1.05%

(1)

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.

(2)

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.

(3)

A CDSC of 1.00% may be assessed on Class C shares if they are redeemed before the first anniversary of their

purchase.

(4)

For the period from March 1, 2025 through February 28, 2026, Lord Abbett Distributor LLC (“Lord Abbett Distributor”) has

contractually agreed to waive the Fund’s 0.10% Rule 12b-1 fee for Class F shares. This agreement may be terminated

only by the Fund’s Board of Trustees.

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 – Micro Cap Growth Fund

Class

If Shares Are 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

707

987

1,287

2,137

707

987

1,287

2,137

Class C Shares

316

667

1,144

2,271

216

667

1,144

2,271

Class F Shares

115

380

666

1,480

115

380

666

1,480

Class F3 Shares

107

334

579

1,283

107

334

579

1,283

Class I Shares

115

359

622

1,375

115

359

622

1,375

Class R2 Shares

176

545

939

2,041

176

545

939

2,041

Class R3 Shares

166

514

887

1,933

166

514

887

1,933

Class R4 Shares

140

437

755

1,657

140

437

755

1,657

Class R5 Shares

115

359

622

1,375

115

359

622

1,375

Class R6 Shares

107

334

579

1,283

107

334

579

1,283

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 122% of

the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

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 micro-cap

companies. A micro-cap company is defined as a company having a market

capitalization at the time of purchase that is under $1 billion or falls within the

market capitalization range of companies in the Russell Microcap

Index. The Fund

uses fundamental analysis to look for micro-cap companies that appear to have the

potential for more rapid growth than the overall economy. The Fund seeks to

identify micro-cap companies that generally exhibit faster-than-average gains in

earnings and that the portfolio management team expects to continue profit growth at

a high level. The Fund evaluates companies based on an analysis of their financial

statements, products and operations, market sectors, and interviews with

management.

Equity securities in which the Fund may invest include common stocks, preferred

stocks, equity interests in trusts (including real estate investment trusts 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”),

Global Depositary Receipts (“GDRs”), and other similar depositary receipts. In