The Internal Revenue Service said Wednesday it has a total of $1 billion worth of unclaimed tax refunds waiting for people who have not filed a 2013 income tax return.

The IRS estimates half the refunds are over $763, while the other half are less than that amount. Taxpayers can claim their refunds by filing a 2013 federal return by Tuesday, April 18, 2017, the filing deadline for this year.

"We’re trying to connect a million people with their share of 1 billion dollars in unclaimed refunds for the 2013 tax year,” said IRS Commissioner John Koskinen in a statement. “People across the nation haven’t filed tax returns to claim these refunds, and their window of opportunity is closing soon. Students and many others may not realize they’re due a tax refund. Remember, there’s no penalty for filing a late return if you’re due a refund.”

The tax laws give people three years to claim refunds for tax returns they have not yet filed. If they don’t file a return within that time, the refund becomes the property of the U.S. Treasury. To claim a 2013 tax refund, taxpayers need to properly address mail and postmark their tax return by April 18, 2017.

However, even then, they may not receive the money. The IRS warned it may still hold onto the 2013 tax refund check if taxpayers have not yet filed their tax returns for 2014 and 2015. The tax refund will also be applied to any amounts still owed to the IRS or a state tax authority. It could also be used for unpaid child support or past due federal debts, such as student loans.

Here are the state-by-state breakdowns of individuals who may be due 2013 tax refunds, according to IRS estimates:

State or District

Estimated

Number of

Individuals

Median

Potential

Refund

Total

Potential

Refunds*

Alabama

18,100

$729

$17,549,000

Alaska

4,700

$917

$5,665,000

Arizona

24,800

$650

$22,642,000

Arkansas

9,900

$722

$9,571,000

California

97,200

$696

$93,406,000

Colorado

20,200

$699

$19,454,000

Connecticut

11,500

$846

$12,691,000

Delaware

4,300

$776

$4,321,000

District of Columbia

3,200

$762

$3,341,000

Florida

66,900

$776

$67,758,000

Georgia

34,400

$671

$32,082,000

Hawaii

6,500

$793

$6,876,000

Idaho

4,500

$619

$3,919,000

Illinois

40,000

$834

$42,673,000

Indiana

21,700

$788

$22,060,000

Iowa

10,200

$808

$10,193,000

Kansas

11,100

$746

$10,700,000

Kentucky

12,900

$772

$12,627,000

Louisiana

20,300

$767

$21,209,000

Maine

4,000

$715

$3,645,000

Maryland

22,200

$770

$23,080,000

Massachusetts

23,000

$838

$24,950,000

Michigan

33,600

$763

$33,998,000

Minnesota

15,600

$691

$14,544,000

Mississippi

10,400

$702

$10,041,000

Missouri

22,400

$705

$20,787,000

Montana

3,600

$727

$3,480,000

Nebraska

5,300

$745

$5,084,000

Nevada

12,300

$753

$12,078,000

New Hampshire

4,400

$892

$4,930,000

New Jersey

29,900

$873

$33,207,000

New Mexico

8,100

$753

$8,162,000

New York

54,700

$847

$59,416,000

North Carolina

29,800

$656

$26,874,000

North Dakota

2,900

$888

$3,209,000

Ohio

36,000

$749

$34,547,000

Oklahoma

17,700

$773

$17,979,000

Oregon

15,500

$658

$14,188,000

Pennsylvania

39,400

$835

$41,078,000

Rhode Island

2,900

$796

$2,906,000

South Carolina

12,100

$674

$11,267,000

South Dakota

2,700

$823

$2,709,000

Tennessee

19,500

$743

$18,829,000

Texas

104,700

$829

$115,580,000

Utah

7,900

$667

$7,443,000

Vermont

2,000

$747

$1,859,000

Virginia

29,000

$752

$29,578,000

Washington

27,600

$829

$30,330,000

West Virginia

5,000

$855

$5,258,000

Wisconsin

12,700

$675

$11,619,000

Wyoming

2,800

$911

$3,189,000

Totals

1,042,100

$763

$1,054,581,000

* Excluding the Earned Income Tax Credit and other credits.

Michael Cohn

Michael Cohn

Michael Cohn, editor-in-chief of AccountingToday.com, has been covering business and technology for a variety of publications since 1985.