The Senate sent the White House a bill on Tuesday giving nearly 4 million veterans and survivors a 1.7 percent increase in their monthly benefit payments next year.
Democrats said the normally routine measure was delayed for weeks because an unidentified Republican senator objected to it.
Republicans were not given enough time to ensure that all senators were okay with the bill, said Don Stewart, a spokesman for Minority Leader Mitch McConnell. He said the clearance process was completed soon after Congress adjourned for the elections and that Democrats could have brought the bill up if necessary.
When the Senate returned this week, it acted quickly to ensure that checks issued beginning in January reflect the adjustment for the higher cost of living.
The House approved the measure in July. The bill now goes to President Barack Obama for his signature.
Sen. Patty Murray of Washington state, a Democrat who chairs the Senate Veterans Affairs Committee, welcomed the financial boost.
"Particularly in this difficult economy, our veterans deserve a boost in their benefits to help make ends meet," Murray said.