Why was there an increase in the Massachusetts Income Tax withholding in my latest paycheck?

The Commonwealth of Massachusetts allows for a tax deduction for Social Security (FICA) and Medicare taxes up to $2,000. The MIT payroll system takes this deduction into account when calculating how much to withhold for your Massachusetts income tax. Once the Social Security and Medicare year-to-date balances reach $2,000, your effective MA tax withholding will be slightly higher. This adjustment occurs each calendar year.