I am an organized person. I managed projects for thirty years. I still managed to botch my Medicare enrollment.

My Mistake

My 65th birthday was in March. The initial enrollment period starts three months before your birthday month and ends three months after. That means I had from January through June.

I knew this. I had it on my calendar. But I was also dealing with a job transition, selling a house, and helping my daughter move. Medicare paperwork kept getting pushed to "next week."

I finally enrolled in August — two months late.

The Consequence

Late enrollment in Part B triggers a penalty of 10% for each 12-month period you were eligible but not enrolled. My two-month delay means a permanent premium increase. It is not much in dollar terms, but it never goes away. I will pay that penalty every month for the rest of my life.

Five Things I Wish Someone Had Told Me

1. Start three months early, not one. The paperwork takes longer than you think. Start the process at least 90 days before your 65th birthday.

2. Medicare and your employer plan overlap is confusing. If you are still working at 65 with employer coverage, the rules are different. Talk to your HR department AND Medicare — do not rely on just one source.

3. Medigap vs. Medicare Advantage is the most important decision. This choice affects your healthcare for years. Medigap (supplemental insurance) gives you more flexibility but costs more monthly. Medicare Advantage often has lower premiums but restricts your network. Research both. Do not let an insurance agent make this decision for you.

4. Part D (prescription drug coverage) has its own enrollment window. Missing this also triggers a penalty. If you do not need drug coverage now, you might still want to enroll in a basic plan to avoid the future penalty.

5. The SHIP program exists and is free. Every state has a State Health Insurance Assistance Program with free counselors who help with Medicare decisions. They are not selling anything. I found out about SHIP after I made my mistakes. Use them before you make yours.

The Bottom Line

Medicare is not difficult, but it is unforgiving. The deadlines are real, the penalties are permanent, and the system assumes you know the rules. You probably do not.

Start early. Get help. Do not be me.