Senators involved in the informal talks say they’ve openly discussed potential reforms that have been on the table for a while, including raising the taxable wage cap or changes to the age threshold for retirement.

But lawmakers are looking for areas of potential bipartisanship.

One idea that has come up in ongoing talks is a special investment fund that members say would help shore up the program’s solvency, after a recent estimate put its exhaustion date less than a decade out.

Sen. Mitt Romney (R-Utah), among the senators involved in the effort, said the idea would allow the country “to be able to borrow at low interest rates and invest in the growth of our economy, and perhaps economies of other nations as well.”

“That’s what other retirement funds do around the world, in corporations and in the railway world, and it creates a substantial source of revenue,” he told The Hill, adding if the investments “didn’t do terribly well, we would kick in through other sources and make sure that we don’t threaten in any way the benefits of recipients.”

Senators have been tight-lipped about other proposals under discussion, as the group works to keep talks from becoming politicized amid a high-stakes partisan battle brewing over the nation’s debt limit.

“It’s a really easy third rail to use on both sides of the aisle, if you want to go after an opponent,” Sen. Mike Rounds (R-S.D.), another senator who’s been a part of the talks, said this week while describing efforts to keep “presidential politics out of it.”

Lawmakers say they hope to potentially have a plan later this year.

“I sure hope so,” Sen. Bill Cassidy (R-La.) told reporters when asked about the prospect on Wednesday.

Read the full report at TheHill.com.