The federal government could reach the maximum amount of money that the U.S. Department of the Treasury is allowed to borrow as soon as Dec. 15.

If Congress doesn’t act to fix that limit, known as the debt ceiling, there could be big ramifications for the timeliness of government payments that people rely on.

A new analysis from the Bipartisan Policy Center explores what could happen if that date passes without a new deal to fund the government.

“Realistically, on a day-to-day basis, fulfilling all payments for important and popular programs [e.g., Social Security, Medicare, Medicaid, defense, military active duty pay] would quickly become impossible,” the Bipartisan Policy Center states.

Between Dec. 21 and Jan. 28 — what the Bipartisan Policy Center calls the “X date” — the Treasury Department would have insufficient cash to fund its obligations.

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“It’s very clear from that range and from the risks that we are seeing that in order to avoid significant risk of crossing the X date, Congress would need to act before they go out for the holiday recess,” said Shai Akabas, director of economic policy at the Bipartisan Policy Center, during a Friday press briefing.

There’s a higher amount of pressure at the beginning that date range due to the fact that the Treasury Department could already have low cash levels while large payments will come due at the end of the year, Akabas said. A $118 billion transfer to the Highway Trust Fund scheduled for Dec. 15 will add to the government’s debt.

Within several weeks of running out of cash, the Treasury Department would be unable to pay approximately 35% of all payments due, including those to individuals and families, according to the analysis.

That government would have two likely options — prioritize some payments over others, or delay paying all of its bills.

If Treasury prioritized payments, it could fund about $317 billion in payments to programs like Medicare and Medicaid, Social Security, federal salaries, nutrition assistance and veterans benefits, according to one scenario from the Bipartisan Policy Center.

But it would then fall short in about $173 billion in other payments for areas like housing and rental assistance programs, civil service and railroad retirement benefits, unemployment insurance benefits or Supplemental Security Income benefits.

Alternatively, the Treasury Department could choose to delay all bills.

If the debt limit were reached on Dec. 21, for example, Medicaid payments to states that were supposed to go out that day would not go out until Dec. 22, federal salaries dated Dec. 23 could get pushed to Dec. 28 and small business loan forgiveness slated for Dec. 27 would be delayed to Dec. 30, the Bipartisan Policy Center estimates.

Meanwhile, Social Security checks slated for Dec. 22 would not be sent until Dec. 27. Those delays would get longer with the next payments dated Jan. 3, which would not go out until Jan. 14, according to the Bipartisan Policy Center’s example.

Notably, because Social Security payments are made through dedicated trust funds, running up against the debt ceiling would not interfere with the program’s financing, experts say.

The U.S. government could avoid running past the deadline to fix the debt ceiling, as it has done in the past. Most recently, President Joe Biden signed legislation on Oct. 14 to increase the debt limit by $480 billion.

On Friday, Reps. Scott Peters, D-Calif., and Jodey Arrington, R-Texas, unveiled legislation aimed at changing how the government handles the issue.

Their bill, called the Responsible Budgeting Act, aims to permanently diffuse the debt limit and address underlying fiscal challenges with specific proposals to reduce the debt.

This proposal has been reviewed by key players in Congress and in the executive branch, according to Bipartisan Policy Center’s Akabas.

“I know that this proposal has been circulated widely,” Akabas said. “That doesn’t mean that it will necessarily advance, but it does have momentum.”