The deadline for service members, veterans and beneficiaries to apply for retroactive “stop loss” pay for post-9/11 military service is fast approaching.

The special pay under the 2009 War Supplemental Appropriations Act applies to those whose service was involuntarily extended under stop loss between Sept. 11, 2001, and Sept. 30, 2009.

Those who meet the criteria must submit an application by Sunday, Oct. 21.

The retroactive payment amounts to $500 for each month of extension, with an average benefit of $3,700, according to the Defense Department.

Information on the special pay and links to the application are available at

According to the Pentagon, the military services have tried to contact those eligible via mail, the Department of Veterans Affairs, veteran and military service organizations, social networks and media outreach.

“But there is still money left to be claimed, and the deadline is approaching,” the Defense Department said in a statement.

As of early October, 98,000 claims have been paid and $352 million appropriated, the Pentagon said.