Do i need to fill out form 8889-T if the HSA account is closed? I do not work there anymore

Did you get a 2017 Form 1099-SA? Did you take any distributions from the HSA last year (before or after you left the employer)?

You must file Form 8889 if any of the following applies for tax year 2017.

• You (or someone on your behalf, including your employer) made contributions in the tax year to your HSA.
• You received HSA distributions during the tax year
• You must include certain amounts in income because you failed to be an eligible individual during the testing period
• You acquired an interest in an HSA because of the death of the account beneficiary.

In short, you are not required to file form 8889 just because you have (or had) an HSA, but only if you had some activity in your HSA during the tax year.