I found this info...
[Medicare Information
Information about Medicare changes for 2022, when announced, will be available at
Medicare.gov: the official U.S. government site for Medicare | Medicare. For Social Security beneficiaries receiving Medicare, Social Security will not be able to compute their new benefit amount until after the Medicare premium amounts for 2022 are announced. Final 2022 benefit amounts will be communicated to beneficiaries in December through the mailed COLA notice and my Social Security’s Message Center.]
Cost-of-Living Adjustment (COLA) Information | SSA