A new form should be coming to you from the employer - the 1099-SA which includes details that you'll need for your taxes. You'll also want to have a good handle on the amount spent from the HSA toward qualified medical expenses.
Unspent money in the HSA may be taxable (wtf?)... and sadly, I didn't know this. I submitted my tax return electronically 24 hours before I got the form.
And even though the Federal Government isn't going to start receiving electronically filed taxes, I can't 'pull back' my submitted tax return. I have to wait for the Government to process it next month and either send it back for corrections or send me my refund... and then I can file a corrected or amended return.
24 hours... if I'd just waited it would have been simpler....