@Buckguest
MAGI for determining your Medicare premiums is your AGI plus tax-exempt interest. The calculation of your Medicare premiums uses your MAGI from two years earlier. Your 2023 premiums will be based on your 2021 MAGI. On your 2021 tax return, the MAGI for calculating Medicare premiums is Form 1040 line 11 plus line 2a.
Your age and when you retired have nothing to do with your MAGI.
