You can ask the Social Security Administration to reconsider your income-related monthly adjustment amount or IRMAA.
As noted by the Social Security Administration:
If your income has gone down due to any of the following situations and the change makes a difference in the income level considered by the Social Security Administration, contact the Social Security Administration and explain that you have new information and may need a new decision about your income-related monthly adjustment amount based on the following:
You married, divorced, or became widowed;
You or your spouse stopped working or reduced your work hours;
You or your spouse lost income-producing property due to a disaster or other event beyond your control;
You or your spouse experienced a scheduled cessation, termination, or reorganization of an employer’s pension plan; or
You or your spouse received a settlement from an employer or former employer because of the employer’s closure, bankruptcy, or reorganization.
If any of the above applies to you, the Social Security Administration needs to see documentation verifying the event and the reduction in your income. The documentation you provide should relate to the event and may include a death certificate, a letter from your employer about your retirement, or something similar. If you filed a Federal income tax return for the year in question, you need to show the Social Security Administration your signed copy of the return.