How is Social Security taxed?

The calculation uses combined income: your adjusted gross income, any tax-exempt interest, and half of your Social Security benefit. Below the first threshold none of the benefit is taxable; between the thresholds up to half is; above the upper threshold up to 85% is. Note that it is the portion that becomes taxable, not the tax rate.

Because the thresholds are not indexed, more households cross them every year. Withdrawals from a traditional retirement account raise combined income and can therefore make more of the benefit taxable, which is why the order you draw from accounts is worth planning.

An estimate for planning, not a quote. Medicare and the Marketplace set your real figures.