code w in box 12 is specific for contributions under a cafeteria plan to an HSA. ask the employer to provide documentation that the money was sent to the trustee/custodian. also, ask for the name of the custodian and phone number so you can call and get the required tax forms you need for filing. you may eventually need the help of a tax pro and possibly need to contact the IRS if the W-2 is incorrect and they refuse to correct it.
