I contributed $1200 to my HSA through pre-tax payroll deductions and my employer added $500; box 12 shows only $1200. I have e-mailed HR and also called and I can't get a straight answer. Today the HR person said that box 12 is only for pre-tax deductions and their contribution was "post-tax". I have never heard of employer contributions being designated as either post or pre-tax, just employee contributions. She also said they "used to" put the amount in that box but don't anymore. The IRS instructions still say both go in there so I'm at a loss to understand what's going on. What I do if they won't change the W2?