WASHINGTON (AP) — The House has passed legislation that would provide full Social Security benefits to millions of people, pushing it one step closer to becoming law.

The Social Security bill on Tuesday won bipartisan support in the House, 327-75, in what is now the lame-duck period for Congress. The bill now heads to the Senate, where passage is not assured despite considerable support.

Here’s what to know about the legislation and what could happen next.

WHAT DOES THE BILL DO?

Decades in the making, the bill would repeal two federal policies — the Windfall Elimination Provision and the Government Pension Offset — that currently limit Social Security payouts for roughly 2.8 million people, according to reports from the Congressional Research Service.

The policies broadly reduce payments to two groups of Social Security recipients: people who also receive a pension from a job that is not covered by Social Security and surviving spouses of Social Security recipients who receive a government pension of their own.

People who worked in state, local and federal government jobs have been heavily affected by the policies, as have teachers, firefighters and police officers, according to lawmakers and advocates.

Both provisions would be repealed by the bill, thereby increasing Social Security payments for many.

WHAT WOULD BE THE COST OF EXPANDING THE BENEFITS?

The budgetary effect of the legislation is considerable, adding an estimated $195 billion to federal deficits over 10 years, according to the Congressional Budget Office.

That means more fiscal strain on the Social Security Trust funds, which were already estimated to be unable to pay out full benefits beginning in 2035. Some conservatives in the House attempted to block the legislation due to its cost.

Supporters of the bill in the House acknowledged the fiscal impact but said it was a matter of fairness.

“For more than 40 years, the Social Security trust funds have been artificially propped up by stolen benefits that millions of Americans paid for and that their families deserve,” said Reps. Garret Graves, R-La. and Abigail Spanberger, D-Va., the lead sponsors of the bill in the House.

“The time to put an end to this theft is now,” they said.

WHAT HAPPENS NEXT?

The Social Security bill has 63 sponsors in the Senate — a significant tally because 60 votes are needed to pass most legislation in the chamber.

Sens. Sherrod Brown, D-Ohio, and Susan Collins, R-Maine, the lead sponsors, have urged colleagues to take up the bill as soon as possible.

But the Senate has a jam-packed schedule in the remaining weeks of the year, with government funding, disaster relief and an annual must-pass defense bill likely to eat up considerable floor time.