When to sign up for Medicare: the windows, the penalties and the Florida Medigap rules

Medicare has several windows, and each controls a different decision. Mixing them up is the most common way people end up with a gap or a penalty.

If you sign up for Part B in the 3 months before your birthday month, coverage starts the first day of your birthday month. If you sign up in the birthday month or the 3 months after, coverage starts the following month. Premium-free Part A starts the month you turn 65, or the month before if your birthday is on the 1st (Medicare.gov).

If you already receive Social Security, you're usually enrolled in Parts A and B automatically. Otherwise you apply through Social Security.

You can delay Part B without a penalty if you have group health coverage based on your own or your spouse's current employment. The Special Enrollment Period lasts until 8 months after the employment or the coverage ends, whichever happens first (Medicare.gov). To use it, Social Security needs proof of the group coverage, usually a form completed by the employer.

Three traps catch people:

COBRA and retiree coverage don't count. Neither is coverage from current employment. Enrolling in COBRA doesn't extend the 8 months.

Small employers. With an employer of fewer than 20 employees, Medicare is generally the primary payer at 65, so the group plan may pay little if you skip Part B. Ask the plan in writing (Medicare.gov).

Health savings accounts. If you sign up for Part A after 65, it can start up to 6 months back, though not before the month you turned 65 (Medicare.gov). Medicare advises stopping HSA contributions at least 6 months before you apply, to avoid a tax penalty (Medicare.gov); confirm the timing with a tax adviser.

The Part B penalty is 10% of the standard premium for each full 12-month period you went without Part B when you could have had it, and it lasts as long as you have Part B. The Part D penalty is 1% of the national base beneficiary premium for each month you went 63 days or more without a drug plan or other creditable drug coverage, and it lasts as long as you have drug coverage (Medicare.gov). People who qualify for Extra Help, or who enroll in a Medicare Savings Program, generally avoid these penalties; see Medicare Savings Programs in Florida.

Federal law gives a one-time 6-month Medigap open enrollment that starts the first month you're 65 or older and in Part B. During it, a company can't refuse to sell you any Medigap policy it offers or use your health to set the price (Medicare.gov). The window doesn't repeat each year.

Florida adds two protections. The same 6-month window applies to Floridians under 65 who are on Medicare because of a disability or end-stage renal disease and are in Part B. And a Floridian in Part B can buy a Medigap policy without health screening during the 2 months after group health coverage ends (Fla. Stat. 627.6741(1)(a)). After those windows, insurers can generally underwrite. The comparison of Medicare Advantage and Medigap is covered in Medicare Advantage vs Medigap in Florida.

Medicare pays for only limited skilled nursing care, so enrollment choices don't replace long-term care planning. For free, unbiased counseling, Florida's SHINE program is available at 1-800-963-5337. If a nursing home stay is possible, see Medicaid planning in Florida.