Before the passage of the tax bill, 64% of seniors didn’t pay taxes on their Social Security benefits, according to a June report from President Donald Trump’s Council of Economic Advisers. Under the new legislation, 88% won’t pay taxes on those benefits, the report estimated.

A provision in Trump's tax and budget law gives seniors 65 and older a new deduction that offsets Social Security taxes for most retirees. While it helps many keep more money, it also accelerates the program's insolvency.