The provision emerged from President Donald Trump’s campaign pledge to end taxes on Social Security. But experts say many are excluded.

The Senate also pulled out a change to the Pell Grant program, which provides federal aid to low-income students to attend colleges and universities. Right now, students are considered full time and qualify for the maximum amount of aid if they take 12 credits a semester.

The GOP megabill has new tax breaks aimed at low- and moderate-income households, and spending cuts that could make it harder for some to receive public assistance or hold onto health insurance.