I think that so far I have overpaid my 2019 Medicare Premiums by approximately $ 1400. I was confused because last year my payments went up due to IRMAA.
I have not been receiving bills and cannot access concrete payment information for my account online.
What should I do?

Hi,

If you believe that your Medicare premiums have been incorrectly increased due to IRMAA, you should contact Social Security and request a new determination. You will then be asked to complete a form SSA-44 (https://www.ssdfacts.com/forms/SSA-44.pdf) and submit any required documentation.

Best, Jerry