The rules
Provisional income = other income + tax-exempt interest + half of benefits. Below $25,000 ($32,000 joint) nothing is taxable; up to $34,000 ($44,000) up to 50%; above that up to 85%. These thresholds are not indexed for inflation.
FAQ
Is Social Security taxed after 65?
It can be, depending on your other income; the extra $6,000 senior deduction (2025–2028) reduces the tax for many.
Sources (checked Nov 6, 2026): IRS Publication 915; IRC sec. 86.