Where do I enter Medicare Premium reimbursement from an HRA account?

Medicare Premiums you paid that are reported on your 1099-SSA are automatically transferred to Medical Expenses in TurboTax. 

 

In Medical Expenses section (under Deductions & Credits), continue to a screen asking about 'reimbursements' where you can enter the amount you were reimbursed for your premiums. 

 

You will be able to see the Medicare Premiums and Reimbursement amounts on the Medical Expenses Worksheet, Lines 2c and 13a when you review your return with worksheets. 

 

Here's more info on Medical Expenses.