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Pay & Leave Pay Administration

Fact Sheet: Computation of Interest on Back Pay System

This program computes the amount of interest due on disbursements of back pay issued under the authority of 5 U.S.C. 5596.

Back Pay Interest Rates

Back pay interest is computed using certain interest rates established by the Secretary of the Treasury under 26 U.S.C. 6621(a)(1). The interest rate is updated quarterly (January 1, April 1, July 1, and October 1). OPM maintains a web page that contains a table of these quarterly interest rates.

Program Downloading Instructions

We strongly suggest that users view and print the Read Me file before attempting to download and operate the back pay interest program.

Download the Program and Documentation

OPM Computation of Interest on Back Pay System Help Documents

The latest versions of the Help document files are included in the zip file above. After downloading the zip file, click on the filename to view and/or download the file. When these Help documents are updated, you will need to download and copy any updated version into the folder on your computer containing the OPM Back Pay Interest System (by default: c:\ProgramFiles\OPM Back Pay Interest System).

You can compare the file dates of the Help documents on your computer to the dates in the above table by doing the following:

  1. Run Windows Explorer
  2. Select the 'Detailed View' (View-Details)
  3. Locate the 'OPM Back Pay Interest System' folder
  4. Find file dates in the 'Modified' Column.