Which factor determines if a retired worker’s social security benefits are taxable?

The taxation of a retired worker's Social Security benefits is determined by the total income of the individual, which includes half of the Social Security benefits received. This calculation is essential because it helps to establish the individual's provisional income, which is compared to the IRS-established thresholds to determine if the benefits are subject to taxation.

If a retiree’s provisional income exceeds certain limits, a percentage of Social Security benefits may become taxable. For most individuals, if their provisional income is above $25,000 (or $32,000 for married couples filing jointly), then up to 50% or even 85% of their benefits may be taxable, depending on the amount of their income.

Factors such as the age of the worker, the amount of premiums paid into Social Security, or the number of dependents do not directly influence the taxability of benefits. Instead, it is the overall income situation that dictates whether benefits will be taxed, which is why considering all income, including half of Social Security, is paramount in determining tax obligations.