How do I solve an accidental violation of Medicare's 6-Month look-back HSA contribution prohibition?

I’m 67 and worked past 65, not enrolling in SS, Medicare A or B. Therefore, I contributed to my corporate HSA through October 2020. I stopped contributing immediately when, upon my research, I heard about Medicare part A imposing a 6-month lookback period within which no HSA contributions are allowed. As such I accidently contributed for a few months before stopping these contributions.

The problem is, I am retiring the end of January 2021 and upon conducting my SS/Medicare sign up interview 1/11/21, the agent suggested one solution was to postpone receiving benefits until May, AFTER the 6 months of non-contribution expires. This is NOT viable! My corporate health insurance etc. ends 1/31/21 and I must start SS, Medicare parts A & B 2/1/21.

What is the solution? Can I withdraw “excess contributions” for the months leading up to my application date? Also, what exactly is the date specified by the Tax code STARTING the 6-month look back period? Is it February 1st when I want to receive benefits? Maybe its 1/13/2021 when I submitted my “Application for Enrollment in Medicare…”? The agent seemed to indicate it was the first time I talked with a SS/Medicare agent in mid-November to schedule my COVID enrollment interview appointment. This will help me know how much I need to withdraw.

I would be fine removing contributions, (<$1,000) which my research leads me to believe are considered as excess contributions, deposited during the 6-month look back period. How do I withdraw these deposits?

Another possibility may be paying a penalty in order to move forward. However, one of your posts suggests that a penalty might continue for as long as I held HSA assets.

Finally, both the IRS Publication 969 about HSAs and the “Medicare & You Handbook” provide the rules, but not corrective paths if the 6-month look back rule is accidently violated. The handbook states, “To avoid a tax penalty, you should stop contributing to your HSA at least 6 months before you apply for Medicare.” Yes, BUT what if I didn’t? What do I do to fix it? I’m certainly not the only one in this situation.