FICA Explained: Social Security and Medicare on Your Stub

Two programs, one acronym

FICA bundles Social Security (OASDI) and Medicare Hospital Insurance. Employers typically match employee amounts for W-2 wages.

These are not “optional fees,” but they are real paycheck friction you should count when comparing jobs or raising contribution rates.

Wage base awareness

Social Security tax generally stops accruing above an annual wage base; Medicare does not stop in the same way and may include additional thresholds for high earners.

High earners therefore see FICA mix change across the year — January stubs can look different from December stubs.