I have an old HSA account that I no longer make contributions to but used it for medical distributions this past tax year. Do I need to report it on my tax return?

You have to report your distributions. 

The distributions need to be reported which will require form 8889.

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You will get a form 1099-SA from the bank, they have until January 31 to mail it but it might be ready sooner and might be available online.  You must report the distributions and then certify they were all used for medical expenses.  If you don't certify that they were used for medical expenses, the IRS will assume the distribution is taxable and send you a bill for taxes and late fees.