A House subcommittee decided yesterday to make the District of Columbia pay off $15 million more of its long-term debt than it planned and continue to pay for street lighting as long as its plan to transfer those costs to Pepco customers is pending.

The subcommittee said it would be up to the city to find the funds, leaving it to the District government to either cut as much as $25 million from already-squeezed city programs or to look for new sources of revenue to make up the difference.

With those and about a half-dozen other changes, The House Appropriations subcommittee on the District of Columbia, in the first congressional step for the city's 1984 budget, adopted a $1.9 billion budget.

City Budget Director Betsy Reveal said she was "generally pleased" with the budget as approved by the subcommittee. "We got 99 percent of what was requested," she said. "They have honored the District's priorities."

Subcommittee Chairman Julian C. Dixon (D-Calif.) has been skeptical about the city's ability to transfer $12 million in costs for street lighting and traffic signals to District utility customers. The change would have to be approved by the Public Service Commission, and Pepco has said it will challenge the transfer in court.

"The budget should not be predicated on what is now just an idea," Dixon said while adding language that would require the city to pay Pepco on a monthly basis until the issue is finally resolved. "To my knowledge this has not been implemented any other place in the country," he added later.

Reveal downplayed the impact of the language, saying the city believes it can get the transfer accomplished quickly and would have paid its electric bill in any event.

The panel also decided to make the city pay off $20 million of its long-term debt during fiscal 1984, while the city had budgeted only $5 million to pay on an accumulated deficit of $309 million.

Congress has indicated before that it wants this long-term debt eliminated at a faster rate, but city officials have argued that the budget is as tight as it can be this year.

Mayor Marion Barry said at a press conference Wednesday that if Dixon wanted to make those kind of changes it would be up to him to find the funds. But Dixon threw the ball back to the mayor yesterday.

"It is the responsibility of the District under home rule to make those priority decisions," Dixon said.

Other additions the subcommittee made in the budget include:

* $312,000 to keep a five-person crew on city's only fireboat.

* $176,000 and two positions for the D.C. Retirement Board.

* $32,000 to increase staff at the Healing Arts Commission, which licenses and disciplines doctors, but which has taken no action in years on a heavy backlog of complaints against physicians.

* $33,000 and a new position on the staff of the National Guard.

These funds are to be taken out of the city's budget for interest on short-term borrowings, which the D.C. City Council already had reduced from Barry's request of $5 million to $3.75 million.

The subcommittee's budget plan also includes language requiring the city to report to Congress on its plans for closing the police and fire clinic at D.C. Village, which provides free health care to police officers and firefighters, and on how the city plans to provide the services.

The city testified this week that it did not have a plan completed and it could not say how much if any savings there would be from the closing.

"It's doubtful and unclear as to whether there will be a cost-saving," Dixon said.

The House Appropriations Committee is scheduled to act on the budget next week. The Senate subcommittee on the District is scheduled to take testimony from the mayor next week and probably will act on the budget soon after.