Reservist Differential Pay: Three Papers to Pull if You Were Activated Since 2009

Reservist differential pay is one of the quietest entitlements in federal employment, and if you are a federal employee who has been activated since 2009, there may be back pay sitting in your file that nobody ever paid you.

Here is what changed, and the three documents worth pulling this weekend.

How Reservist Differential Pay Works

Congress created the entitlement in 2009, at 5 U.S.C. § 5538. The idea is simple: when a federal employee is called to active duty and their military pay is lower than their civilian pay, the difference gets made up.

The Test OPM Used — and the Test the Supreme Court Applied

OPM never issued regulations on § 5538. It issued policy guidance instead, in 2009, last revised in 2015. That guidance told agencies an employee had to show the deployment was "substantially connected" to a particular war or national emergency.

In April 2025, the Supreme Court rejected that test. In Feliciano v. Department of Transportation, 605 U.S. 38 (2025), the Court held that the statute asks only whether the service coincided in time with a declared national emergency — not whether it was substantively connected to one.

Fifteen Months Later, the Guidance Still Says the Old Thing

On Wednesday, August 12, 2026, a Department of Veterans Affairs attorney who is also a major in the Army Reserve's Judge Advocate General's Corps sued OPM to compel it to issue the regulations. The line from his complaint puts it plainly: "The absence of a binding rule is not incidental to plaintiff's injury; it is the injury." His counsel say they are recruiting additional reservists in preparation for a class case at the Merit Systems Protection Board in the coming weeks.

Three Papers to Pull

• Your activation orders. Every set, going back to March 2009.
• Your civilian leave-and-earnings statements for those pay periods. You are looking for whether a differential was ever paid at all.
• Any denial you received — the email, the memo, whatever form it took — especially if it used the words "substantially connected."

There Is No Filing Deadline

This is what makes reservist differential claims different from nearly everything else in federal employment law. Reservist differential claims reach the Board as USERRA appeals under 38 U.S.C. § 4324(b), and there is no limitations period: 38 U.S.C. § 4327(b) and 5 C.F.R. § 1208.12 both say there is no limit on the period for filing.

That is not permission to wait. Records get harder to find and people move on. But the door is not closed on you, and that is worth knowing if you assumed it was.

What Has Not Happened Yet

To be clear about where things actually stand: nothing has been certified as a class, and no court or Board decision has ordered anyone to pay anything as a result of the August 12 suit. Do not assume a filing exists on your behalf.

The Practical Takeaway

If you were activated and never saw a differential — or you were denied under the "substantially connected" standard the Supreme Court has since rejected — the answer today may be different from the answer you got then. Pull the three documents first. They are what any evaluation starts with.

Legal Disclaimer: This content is for general informational purposes only and does not constitute legal advice. Federal employment situations are fact-specific and time-sensitive. Please consult a qualified federal employment attorney about your specific situation. You can contact Southworth PC at attorneysforfederalemployees.com.