President Joe Biden waves after signing the Social Security Fairness Act during a ceremony in the East Room of the White House on Sunday. Looking on from left are former Rep. Abigail Spanberger, D-Va., and Sen. Susan Collins, R-Maine. Manuel Balce Ceneta/Associated Press

President Joe Biden signed a bill into law that will increase Social Security benefits for millions of Americans, including thousands of Maine teachers, firefighters and police officers.

Maine Sen. Susan Collins, who co-authored the bill, stood by Biden’s side at the White House during the signing Sunday afternoon.

The Social Security Fairness Act will boost Social Security payments to more than 2.5 million retirees across the country — some by as much as $550 a month — by changing the formulas used to reduce benefits for certain beneficiaries, like those on government retirement plans for police officers, firefighters and teachers.

The bill received bipartisan support in both chambers of Congress, passing the House 327-75 and the Senate 76-20.

“Americans who have worked hard all their lives to earn an honest living should be able to retire with economic security and dignity,” Biden said during the ceremony. “The law that existed denied millions of Americans access to the full Social Security benefits they earn by thousands of dollars a year.”

The act ends the Windfall Elimination Provision, which reduced benefits for public employees who don’t pay into Social Security through their government retirement plans, regardless of their contributions through other private-sector jobs. It also eliminates the Government Pension Offset, which decreases payments for surviving spouses if they receive their own government pension.

Collins has been working on the issue for more than two decades and co-authored the bill with Ohio Democrat Sen. Sherrod Brown.

“In 2003 I held the first Senate hearing on these provisions to try to educate my colleagues about it and to start pursuing remedies to it,” Collins said in a phone interview Monday afternoon. “And I just can’t tell you how elated I was to be at the White House yesterday when the president signed our bill into law.”

Collins said 83% of people impacted by the Government Pension Offset are women, usually people who have worked in school systems whose spouse worked in the private sector. When their spouse dies, Collins explained, those women can lose some or all of their spouse’s Social Security benefits because they’re public employees.

She said a total of about 26,500 Mainers will be impacted by the end of both provisions, and said teachers will be one of the most affected groups.

The Windfall Elimination Provision has been top of mind for Maine educators, who say it discouraged people from pursuing careers in teaching, exacerbating the state’s shortage.

Collins said there were two major challenges to getting the bill passed: getting then-Senate Majority Leader Chuck Schumer to bring it to the floor for a vote and overcoming concerns about the financial solvency of Social Security.

On the first matter, she said advocacy groups and senate colleagues worked hard to convince Schumer that the votes were there. And on the second, she said the issues are not mutually exclusive.

“That was a very real problem, but it wasn’t right to unfairly penalize people who had earned benefits in an attempt to address the solvency of the system,” she said. “We definitely need to address the solvency of the system, but perpetuating an unfair system that penalized people who have earned these benefits is not the answer to this overall solvency problem.”

Collins said it will take some time for the Social Security Administration to calculate the benefit changes for the 3 million impacted individuals, but she believes the adjustments could happen as soon as April.

Other members of Maine’s delegation celebrated the news Monday. Independent Sen. Angus King, who signed on as a co-sponsor, described the bill as a long-sought, bipartisan success after it passed in December.

“Across Maine, firefighters, police officers, teachers and other public servants put the well-being of our communities first; it’s past time they receive the benefits they so rightly have earned,” King said in a statement.

Rep. Chellie Pingree, D-1st District, penned an op-ed in the Press Herald Monday lauding the bill’s passage. She said that she has supported an end to the Windfall Elimination Provision and Government Pension Offset since her early days in Congress.

“When my time came to vote ‘Yea’ on the floor, knowing the impact it would have on so many Mainers, the satisfaction I felt was enormous,” she wrote.

Rep. Jared Golden, D-2nd District, also praised the fairness act in a statement Monday.

“Public employees such as teachers and first responders provide some of the most essential services in our country. For too long, people who paid into Social Security were punished for taking those public-sector jobs by government policies that reduced their Social Security benefits,” Golden said. “This law will finally guarantee that they receive the full benefits they earned.”

This story contains material from Bloomberg News.