Your first year on Medicare comes with a learning curve, and most of the mistakes people make aren’t about big decisions — they’re small oversights that turn into bigger headaches down the road. Here are five of the most common ones, and how to avoid them.
1. Missing the Initial Enrollment Period Window
Your Initial Enrollment Period runs seven months — the three months before your 65th birthday month, your birthday month, and the three months after. Enroll late without qualifying employer coverage, and you could face a late enrollment penalty for Part B that sticks with you for as long as you have Medicare, plus a gap in coverage while you wait for the next enrollment window. The fix is simple in theory: mark your enrollment window on the calendar the moment you know your birthday month is approaching, and don’t wait for a reminder that may never come.
2. Assuming Original Medicare Covers Everything
Original Medicare (Part A and Part B) is comprehensive, but it isn’t complete. It doesn’t cover most prescription drugs, and it leaves you responsible for coinsurance and deductibles with no out-of-pocket maximum. Many new enrollees are surprised the first time they get a hospital bill and realize Part A’s deductible ($1,676 per benefit period in 2026) applies per benefit period, not per year — meaning multiple hospital stays in the same year can mean multiple deductibles. Pairing Original Medicare with a Part D plan and, often, a Medigap policy closes these gaps, but you have to choose that coverage — it doesn’t happen automatically.
3. Not Checking the Drug Formulary Before Enrolling in a Part D or Advantage Plan
It’s tempting to pick a Part D plan based on premium alone, but the premium is only part of the cost picture. Each plan has its own formulary — the list of covered drugs and their tiers — and if your medications aren’t on it, or sit on a high tier, your actual costs can be far higher than the sticker price suggested. Before enrolling in any plan with drug coverage, run your actual medication list against that plan’s formulary, not just its overall reputation.
4. Ignoring Provider Networks on Medicare Advantage Plans
If you choose a Medicare Advantage plan, your doctors and specialists need to be in-network for the plan to work well for you. New enrollees sometimes assume any provider who “takes Medicare” is automatically covered under their Advantage plan, but these plans have their own networks separate from Original Medicare. Confirm your specific doctors are in-network before you enroll, not after your first appointment gets an unexpected bill attached.
5. Not Reviewing Coverage Every Year
Medicare isn’t a “set it and forget it” system. Plans change their premiums, formularies, and networks every year, and your own health needs change too. Skipping your annual review during the Annual Enrollment Period (October 15 – December 7) means you could be paying for coverage that no longer fits — or missing out on a better-priced option that would.
A Simple First-Year Checklist
- Confirm your Initial Enrollment Period dates well before your 65th birthday.
- Decide early whether you’ll pair Original Medicare with Medigap and Part D, or choose a Medicare Advantage plan instead.
- Check your medications against any plan’s formulary before enrolling.
- Verify your providers are in-network if you choose Medicare Advantage.
- Put a reminder on your calendar to review your coverage every fall.
If you’re navigating your first year and want a second set of eyes on your choices, our turning 65 guide is a solid starting point, and our FAQ page covers many of the questions that come up most in year one.
Bottom Line
Most first-year Medicare mistakes come from moving too fast on enrollment or too slow on annual review. A little extra attention at the start — and a habit of checking your coverage every fall — prevents the majority of the headaches new enrollees run into. If you want to build a stronger foundation in the basics, our free course at LearnMedicare.org is a good next step.
Price Services Group, LLC is not affiliated with or endorsed by the U.S. government or the federal Medicare program. NPN: 18530055 | Agency NPN: 20387435
Have questions? Schedule a free review with Kayla Price, a licensed insurance agent at Price Services Group. Call 866-648-1578 or visit priceservicesgroup.com/schedule.