Form 8889 is required if you had contributions to or withdrawals from an HSA. (Contributions made via payroll deduction are recorded on your W-2.) The form is scheduled to be released in an update on 1/26. If you don't include the form, the IRS will assume that your withdrawals or contributions were not allowed, and will send you a bill for additional taxes and penalties. At that point you will have to pay the bill or send them an amended return to fix the problem.
