Maine’s two U.S. senators hope to preserve a savings opportunity for low-income workers who don’t have bank accounts.

The legislation would extend a program started in 2010 that lets taxpayers receive any refund on their federal taxes in the form of a U.S. savings bond, a paper bond that lets buyers earn interest on their money over time.

U.S. Sen. Susan Collins, a Republican who is Maine’s senior senator, called it “an important, low-risk investment option for many individuals,” especially “those without bank accounts or internet access.”

The program gives “Americans across the country a trusted way to save and responsibly manage their money, which is why it makes no sense for Congress to allow the Tax Time Savings Bond program to expire at the end of this tax season,” said U.S. Sen. Angus King, a first-term independent.

“In a rural state like Maine where access to the internet can be unreliable or people may lack access to traditional banking accounts, this program can be a vital savings opportunity,” King said. “We should work to preserve that option, not diminish it.”

In a prepared statement Wednesday, the pair endorsed the bipartisan “Save Access to a Valuable Investment Needed to Generate Savings (SAVINGS) Act of 2017,” sponsored by Collins and U.S. Sen. Patty Murray, D-Wash. King is one of two original co-sponsors, along with U.S. Sen. Amy Klobuchar, D-Minn.

In its first several  years, American taxpayers opted to receive $120 million worth of refunds in the form of savings bonds, a tiny fraction of the money sent by the federal government to taxpayers owed refunds.

The proposed extension legislation calls for the U.S. Treasury Department to keep offering the bond option to taxpayers who can get bonds in their own name or designate an alternative recipient. They currently pay 2.76 percent annual interest.

The Treasury Department stopped selling paper savings bonds at financial institutions in 2012, allowing their purchase instead through Treasury Direct, where accounts are held online.

The only way to get a paper savings bond is through the Tax Time Savings Bond option for Internal Revenue Service returns, something taxpayers can choose by checking the appropriate box on the IRS refund allocation form. If they do, they’ll get a paper savings bond for some or all of their refund.

The paper bond program was destined to close down in 2015, but the Treasury Department kept it going through 2017.

The senators said that with 7 percent of Americans lacking bank accounts and rarely interacting with financial institutions, the paper bond option should remain in place.

About half of the lowest-income Americans lack internet access. Many also have no savings.

“At a time when many workers are finding it harder and harder to get ahead, we should be doing everything we can to provide workers more opportunities to save — not less,” Murray said.