Past delays in addressing Social Security's looming trust fund exhaustion will now make it harder than ever to fix the problem without harming vulnerable people, a former trustee for the program said Wednesday.

“What we’re looking at now, because of the delays to this point, is that it becomes very difficult to enact reforms in a way that doesn’t harm people who simply can’t afford it,” said Chuck Blahous, one of the most recent public trustees for the trust fund and an expert at the libertarian Mercatus Center.

The trust fund is supposed to have two public trustees, one from each party, nominated by the president and confirmed by the Senate. But since 2015, when Blahous and Robert Reischauer saw their terms end, the positions have been vacant.

The two spoke on a call with reporters hosted by the Bipartisan Policy Center following Tuesday’s report from the trustees, mostly Trump cabinet officials, projecting that the combined Social Security trust funds will run out in 2034.

Blahous said that to shore up the system’s finances, it would be necessary to reduce benefits by about a fifth going forward, according to Tuesday’s report. Making up that difference, he said, would likely require changing more than just benefits for high earners.

Speaking on the same call, Social Security’s chief actuary said that Congress “absolutely needs to act” between now and 2034, and that sooner would be better than later.