Form 8889

Form 8889 is an Health Savings Account (HSA) related IRS form. A taxpayer must file Form 8889 in any of the following cases:
Case 1: you must file Form 8889 if you made a contribution to your HSA account.
Case2 : you must file Form 8889 if your employer or somebody else made a contribution to your HSA account on your behalf.
Case 3: you must file Form 8889 if you received an interest in an HSA as a result of the death of the account beneficiary.
Case 4: you must file Form 8889 if you received an HSA distribution during the taxable year.
Case 5: you must file Form 8889 if you over-contributed to your HSA account. This excess contribution will be taxed as income and may be assessed a 10% penalty. One way to reduce any excess contribution in Form 8889 is to withdraw not yet reimbursed qualified medical expenses prior to April 15.
Also, be aware that as long as you (or your spouse for joint filers) received an HSA distribution, you will need to file Form 8889 with Form 1040, even if you have not received any taxable income and therefore were not planning on filing Form 1040.
IRS provides guidance on how to fill out Form 8889 in its "Instructions for Form 8889" guide.