Metro would be reimbursed less than $1 million for its stepped-up inauguration service, under current federal guidelines — much less than the approximately $2.5 million the transit agency requested.

The system spent $5.2 million more than usual from Jan. 17 through Jan. 20, running trains for 22 hours straight Jan. 20 and logging a total of 1.54 million entries into its rail, bus and MetroAccess paratransit systems.

Metro collected about $3 million in fares from the millions of riders who took the system during the inauguration weekend. Officials have estimated that on a normal holiday weekend, the system would have earned $600,000, so the extra traffic left a difference of about $2.4 million.

Carol D. Kissal, Metro’s chief financial officer, said the federal government’s reimbursement guidelines would give the agency less than $1 million.

“They’re looking to stick us for $1.5 million,” said board member Chris Zimmerman, adding that Metro provided the transit system the best day in its history at a cost of $2.5 million.

“We provided the service, and it doesn’t seem quite right,” he said, adding that he was surprised to hear the agency wouldn’t be reimbursed more.

Jan. 19 and Jan. 20 brought in the most rail riders in Metro’s 33-year history, with more than 1.1 million trips on the Jan. 20 inauguration day. Riders took 866,000 trips on the Jan. 19 Martin Luther King Jr. Day holiday.

Inauguration-related expenses for January totaled $3.7 million, according to Metro. Labor costs — primarily overtime — totaled $2.6 million, power and utilities cost $800,000, and fringe expenses were $300,000.