Social Security's retirement trust fund is projected to run out in late 2032.
After that, incoming payroll taxes cover about 78% of scheduled benefits, per the 2026 Trustees Report.
For someone who turns 65 in 2032 and claims at 67, here is the monthly gap in today's dollars if the cut is spread evenly:

Low earner: $1,669 scheduled, $1,302 payable, $367 short
Medium earner: $2,758 scheduled, $2,151 payable, $607 short
High earner: $3,640 scheduled, $2,839 payable, $801 short
Maximum earner: $4,474 scheduled, $3,490 payable, $984 short

The law doesn't say how SSA would handle the shortfall. It can only pay out what comes in, so checks would come smaller or late.
The payable share falls to about 62% by 2100 unless Congress changes something.