sustainable_municipal_bond_fund_summary

LORD ABBETT

MUNICIPAL INCOME FUND

Lord Abbett

Sustainable Municipal Bond

Fund (the “Fund”)

Supplement dated

February

2025

to the

Summary Prospectus, Prospectus, and Statement of

Additional Information of the Fund,

each dated

February

1, 20

, as supplemented

Liquidation of the Fund

February 4, 2025

, the Board of

Directors

of Lord Abbett

Municipal Income Fund

approved a plan of

liquidation (the “Plan”) pursuant to which the Fund will be liquidated and dissolved

. It is currently

anticipated that the liquidation and dissolution of the Fund will be completed on or around

Spring

202

(

the

“Liquidation Date”

Any Fund shares outstanding on the Liquidation Date will be automatically redeemed

on the Liquidation Date. The proceeds of any such redemption will be equal to the net asset value (“NAV”)

of such shares after dividend distributions required to eliminate

any Fund

level taxes are made

the

Fund’s

expenses and liabilities have been paid or otherwise provided for as directed by the Plan

and the

Fund has

distributed to its shareholders of record the remaining proceeds in one or more liquidating

distributions

the Liquidation Date as set forth in the Plan

At any time before the Liquidation Date, shareholders may

▪

Exchange their

Fund

shares for the same class of shares of another

Lord Abbett

Fund, provided

that the exchange satisfies the investment minimum of the Fund selected;

▪

Redeem their Fund shares at the NAV of such shares pursuant to the procedures set forth under

“Purchases and Redemptions” in the prospectus

; or

▪

Do nothing and their

Fund

shares will be redeemed on or about

the Liquidation Date

. However,

shareholders in individual retirement accounts who do not take other action will automatically have

their shares exchanged for shares of

Lord Abbett

Government

& Government Spon

sored

Enterprises

Money Market Fund on or about

the Liquidation Date

In connection with the liquidation of the Fund, the Fund no longer will accept purchase orders or exchange

requests

February 7

, 2025

Capitalized terms used in this Supplement

shall, unless otherwise defined herein, have the same meaning as given in the Prospectus and/or SAIs.

Please retain this document for your future reference.

SUMMARY PROSPECTUS

Lord Abbett Sustainable Municipal Bond Fund

FEBRUARY 1, 2025

CLASS/TICKER

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

LASMX

CLASS F .........

LSMFX

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

LISMX

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

LCSBX

CLASS F3 .......

LSMOX

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 February 1, 2025, as may

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

SUMMARY – Sustainable Municipal Bond Fund

INVESTMENT OBJECTIVE

The investment objective of the Fund is to seek the maximum amount of interest

income exempt from federal income tax as is consistent with reasonable risk.

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 147 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, and I

Maximum Sales Charge (Load) Imposed on Purchases

(as a percentage of offering price)

2.25%

None

Maximum Deferred Sales Charge (Load)

(as a percentage of offering price or redemption

proceeds, whichever is lower)

None

(2)

1.00%

(3)

None

SUMMARY – Sustainable Municipal Bond Fund

Annual Fund Operating Expenses

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

Class

Management Fees

0.32%

Distribution and Service (12b-1) Fees

0.20%

0.85%

(4)

0.10%

None

Other Expenses

2.60%

2.59%

2.60%

Total Annual Fund Operating Expenses

3.12%

3.77%

3.02%

2.91%

2.92%

Fee Waiver and/or Expense Reimbursement

(5)

(2.49)%

Total Annual Fund Operating Expenses After Fee Waiver and/or

Expense Reimbursement

(5)

0.63%

1.28%

0.53%

0.42%

0.43%

(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 18-month 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)

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.

(5)

For the period from February 1, 2025 through January 31, 2026, 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 0.42% for Class F3 and to an

annual rate of 0.43% for each other class. This agreement may be terminated only by the Fund’s Board of Directors.

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: