The Consumer Financial Protection Bureau finalized a rule on Thursday that would limit overdraft charges at large banks and credit unions, a move that federal officials said could help save Americans billions in fees each year.

Whether it will remain in place once President-elect Donald J. Trump returns to power is unclear.

The rule would cap fees that customers are charged when they spend more money than they have in their bank accounts. Federal officials said large banks would have several options to comply. They could cap their overdraft fees at $5, or set their fees at another amount that covers their costs and losses. Alternatively, they could treat overdrafts as a line of credit and provide similar disclosures, including applicable interest rates.

While many banks have moved to reduce their overdraft fees, charges still average around $30 for each instance, according to a recent Bankrate survey.

The rule would apply to institutions with more than $10 billion in assets, which includes about 150 of the nation’s roughly 9,000 banks and credit unions, and take effect in October.

Banking trade groups sharply criticized the rule after the bureau proposed it this year. Some in the industry are expecting the Trump administration, which took a friendly approach to banks during Mr. Trump’s first term, to try to roll it back.

Republican lawmakers could also try to undo it and other Biden administration regulations using an obscure law known as the Congressional Review Act. But given slim Republican majorities in the House and the Senate next year, it is unclear whether they could muster enough support to roll back many rules.