Following is a summary of the federal 2021 payroll tax changes including Social Security, Medicare, Unemployment Tax, Minimum Wage, 401(k) limits, and more.   Print Full 2021 Payroll Tax Alert [PDF]   Social Security / Medicare The wage base increases to $142,800 for Social Security and remains UNLIMITED for Medicare. For Social Security, the tax rate … Continue reading 2021 Federal Payroll Tax Rates