Medicare at 65: What to Do 6 Months Before Your Birthday
Turning 65 in Nashville? Here's the month-by-month Medicare enrollment timeline most people miss — and why the Medigap window is the most important deadline you've never heard of.
Most people spend more time planning their 65th birthday party than they spend planning their Medicare enrollment. That’s not a criticism — Medicare is genuinely complicated, and nobody hands you a clear timeline when the clock starts ticking.
But here’s what the insurance industry doesn’t advertise loudly enough: you have a window, and it closes. Miss it, and you could face lifetime premium penalties, gaps in coverage, or lose your right to buy a Medigap plan without medical underwriting — ever.
This is the timeline we walk every client through at Nashville Insurance Advisors. Here’s what to do, and when.
Why 6 Months Matters
Medicare’s Initial Enrollment Period (IEP) opens three months before your 65th birthday month and closes three months after. That’s a seven-month window to enroll in Parts A and B.
But for Medigap — the supplemental coverage that fills Original Medicare’s gaps — the clock runs differently. Your Medigap Open Enrollment Period is six months, starting the month you’re both 65 and enrolled in Part B. During this window, insurers in Tennessee must sell you any Medigap plan at standard rates, regardless of your health history. No medical questions. No underwriting. No denial.
Once that window closes, Tennessee allows medical underwriting. That means an insurer can review your health history, charge you more, or refuse to sell you a plan altogether. For anyone with a pre-existing condition, this isn’t hypothetical — it’s the difference between having options and not having them.
Six months before your birthday is when the preparation needs to start.
The Month-by-Month Checklist
6 months out — Understand what you’re actually deciding
There are two fundamentally different paths at 65: Original Medicare (Parts A + B) paired with a Medigap supplement, or Medicare Advantage (Part C). These are not interchangeable options. They reflect different philosophies about how you want your healthcare to work.
Medigap plans are standardized by federal law. A Plan G from one insurer covers the exact same benefits as Plan G from another — the only difference is the premium. In Tennessee for 2026, Plan G is the most comprehensive option for new enrollees, covering everything except the Part B deductible ($257/year). Plan N offers lower premiums with small copays for office and ER visits.
This is also the time to contact Tennessee SHIP — the State Health Insurance Assistance Program — at 877-801-0044. It’s a free, unbiased counseling service for Medicare beneficiaries. Use it.
4–5 months out — Confirm your Part A and Part B enrollment
If you’re already receiving Social Security benefits, you’ll be enrolled in Medicare automatically. Your card arrives about three months before your birthday month. If you’re not receiving Social Security yet, you need to actively enroll at ssa.gov or your local Social Security office.
Don’t assume it’s automatic. Many people turning 65 who are still working assume their employer coverage handles it. Depending on your employer’s size, that may or may not be true — and the rules around delaying Part B enrollment are specific enough that a mistake here can cost you.
3 months out — Shop Medigap plans
Because Medigap benefits are standardized, the shopping process is simpler than it looks. You’re comparing premiums across carriers for the same underlying coverage. In Tennessee, the standard options are Plan G (most comprehensive, highest premium) and Plan N (lower premium, small copays). Plan K and Plan L exist for healthier enrollees comfortable with more cost-sharing.
What varies by carrier: premium pricing, rate increase history, and financial stability. An independent advisor can run a comparison across every carrier available in Davidson County — that’s something you can’t easily do on Medicare.gov or by calling 1-800-MEDICARE, which won’t recommend specific plans.
1–2 months out — Add Part D (prescription drug coverage)
Even if you’re in good health and take no medications, skipping Part D carries a late enrollment penalty — 1% of the national base beneficiary premium for every month you go without coverage. That penalty is permanent and added to your premium for life. A low-cost Part D plan is almost always worth carrying just to avoid it.
Your birthday month — You’re enrolled
Your Medigap open enrollment period begins. This is the protected window. Use it.
The Decision Most People Get Wrong
The TV ads for Medicare Advantage are loud, well-produced, and lead with “$0 premium.” They’re not lying — many plans in the Nashville market do carry no monthly premium. But the premium is only part of the picture.
Original Medicare with a Medigap supplement means predictable costs. You pay your premium, and most of your healthcare costs are covered. There are no networks. You can see any doctor or specialist who accepts Medicare — anywhere in the country.
Medicare Advantage means lower premium, potentially, but a network. You’ll need to confirm your doctors are in-network before enrolling. Out-of-network care costs more. Prior authorizations may be required for certain procedures. And if you develop a serious illness and need to switch back to Original Medicare, you’ve lost your guaranteed issue right — medical underwriting now applies.
Neither path is wrong for everyone. But it’s a decision worth making deliberately, not by default.
What an Independent Advisor Does Here
When a Nashville client comes to us approaching 65, Medicare is rarely the only conversation. It connects to everything else: retirement income, long-term care exposure, life insurance coverage that may no longer fit, and whether existing policies still make sense.
That’s the Coverage Blueprint — a structured review of everything you have, everything you’re exposed to, and what actually needs to change. Medicare is often the door that opens that conversation.
If your 65th birthday is in the next six to twelve months, that’s the right time to start — not the month before enrollment. The decisions you make during your Medigap open enrollment window can’t be undone.
Learn more about our Medicare Planning services.
Book a Discovery Meeting — we’ll walk through the timeline together.