# Understand Your W2 Wages ## expand\_more Payroll receives many questions about the W-2. Most of these questions focus on understanding the amounts in the numbered boxes on the W-2. The most common questions relate to why W-2 Wages differ from your final pay stub for the year, and why Federal and State Wages per your W-2 differ from Social Security and Medicare Wages per the W-2. The short answer is that the differences relate to what wage amounts are taxable in each case. The following steps will walk you through the calculations of the W-2 wage amounts and enable you to reconcile these to your final pay stub for the year. **CALCULATING FEDERAL AND STATE TAXABLE WAGES (BOXES 1 & 16)** Use your last pay stub for the year to calculate the taxable wages in boxes 1 and 16 in your W-2. Begin with the Gross Pay YTD (year-to-date) and make the following adjustments, if applicable: Federal Taxable Wage – Adjustments to Gross Pay YTD: Subtract YTD Before-Tax Deductions, which include • Medical • Dental • Vision • FSA Health • FSA Dependent Care • HSA • Parking • T Pass • 403B • 457 Plan Add Employer Paid Benefits Taxable\* for QDP Medical and Dental YTD Add GTL imputed income from Box 12C on your W-2 State Taxable Wage – Adjustments to Gross Pay YTD: Subtract YTD Before-Tax Deductions, which include • Medical • Dental • Vision • FSA Health • FSA Dependent Care • HSA • Parking • T Pass • 403B • 457 Plan Add Employer Paid Benefits Taxable\* for QDP Medical and Dental YTD Add GTL imputed income from Box 12C on your W-2 The resulting amounts should equal Box 1 Federal Wages and Box 16 State Wages on your W-2. Some employees may see a difference between Box 1 Federal Wages and Box 16 State Wages due to the value of certain pre-tax transportation benefits. If you find that after making these adjustments to your Gross Pay YTD per your final pay stub, the result does not match Box 1 Federal Wages and Box 16 State Wages on your W-2, call Central Payroll, 617-495-8500, option 4, for assistance. **CALCULATING SOCIAL SECURITY AND MEDICARE TAXABLE WAGES (BOXES 3 & 5)** The Social Security Wage Base for 2019 was $132,900. To determine Social Security and Medicare taxable wages on your W-2, again begin with the Gross Pay YTD from your final pay stub and make the following adjustments if applicable: Social Security and Medicare Taxable Wage – Adjustments to Gross Pay YTD: Subtract the following: • Before-Tax Medical deductions YTD • Before-Tax Dental deductions YTD • Before-Tax Vision deductions YTD • Before-Tax FSA Health deductions YTD • Before-Tax FSA Dependent Care deductions YTD • Before-Tax HSA deductions YTD • Before-Tax Parking deductions YTD • Before-Tax T Pass deductions YTD Add Employer Paid Benefits Taxable\* for QDP Medical and Dental YTD Add GTL imputed income from Box 12C on your W2 The resulting amount should equal Box 3 Social Security Wages and Box 5 Medicare Wages on your W-2. If you find that after making these adjustments to your Gross Pay YTD per your final pay stub, the result does not match Box 3 Social Security Wages and Box 5 Medicare Wages on your W-2, call Central Payroll, 617-495-8500, option 4 for assistance. **EXPLANATION OF OTHER BOXES ON YOUR W-2** Box 12C: Group term life (GTL) Box 12E: 403B TDA deductions Box 12G: 457 Plan deductions Box 12M: Uncollected Social Security Tax on taxable GTL Box 12N: Uncollected Medicare tax on taxable GTL Box 12P: Excludable moving expenses Box 12T: Adoption benefits Box 12BB: 403B Roth deductions Box 12DD: Cost of employer sponsored Health Insurance Box 12W: Employer contributions and employee elected contributions to HSA See also:- [ How To ](/resource-type/how) - [ Central Payroll ](/service-units/central-payroll)