How to Plan Annual Open Enrollment for Medication Coverage in Medicare

Every year, millions of Medicare beneficiaries miss out on hundreds - sometimes over a thousand - dollars in savings just because they don’t check their medication coverage. If you take regular prescriptions, skipping your Annual Open Enrollment Period (AEP) is like leaving money on the table. Your current plan might have covered your insulin at $10 a month last year, but this year? It’s now a specialty tier drug with a $120 co-pay. That’s not a fluke. It happens. And it’s completely avoidable.

Know the Dates - And Stick to Them

Medicare’s Annual Open Enrollment Period runs from October 15 to December 7 every year. That’s it. If you don’t make a change by December 7, your coverage for 2026 stays exactly as it was in 2025. No extensions. No grace period. No second chances. Changes you make during this window take effect on January 1 - no delays, no exceptions.

This window exists for one reason: plans change. Every single year. Premiums go up. Formularies get rewritten. Pharmacies drop out of networks. What was covered under Tier 2 last year might be Tier 4 this year - meaning your out-of-pocket cost could jump by 30% or more. The Centers for Medicare & Medicaid Services (CMS) reports that about 60% of Part D plans change at least one medication’s coverage status annually. If you don’t look, you won’t know.

Start with Your Current Plan’s Paperwork

Don’t jump straight into comparing plans. Start with what you already have. Look for two documents: the Annual Notice of Change (ANOC) and the Evidence of Coverage (EOC). These arrive in your mailbox around September 30. If you haven’t gotten them by October 10, call your plan directly or log into your account on Medicare.gov.

The ANOC lists every change your plan made for the coming year - premium increases, new deductibles, changes to your drug list, pharmacy network updates. The EOC is the full rulebook: what’s covered, what’s not, how much you pay, and what restrictions apply. Look for three things:

• Any medication you take that’s been moved to a higher tier
• Any medication that’s been removed from the formulary entirely
• Any new prior authorization or step therapy requirements

For example, if you take Ozempic or another GLP-1 drug, check if your plan now requires you to try cheaper alternatives first (step therapy). If they do, and you can’t get an exception, you could be stuck paying full price - over $1,000 a month - until you switch plans.

Use the Medicare Plan Finder Tool - With Your Exact Medications

Go to Medicare.gov/plan-compare. This is the only tool you need. Don’t rely on insurance agents or third-party websites. CMS runs this tool, and it pulls real-time data from every plan in your area.

Here’s how to use it right:

1. Enter your ZIP code.
2. Input every medication you take - including dosage and frequency. Don’t guess. Use the exact name your pharmacist uses.
3. Select "Include Part D plans" and "Include Medicare Advantage plans with drug coverage."
4. Click "Find Plans."

The tool will show you a side-by-side breakdown of each plan’s total estimated cost for your specific drugs in 2026. Look at the "Total Annual Cost" column - not just the monthly premium. A plan with a $0 premium might cost you $1,200 more a year in co-pays because your drugs are on a higher tier.

Pro tip: Filter by "Preferred Pharmacy." If you use CVS, Walgreens, or your local independent pharmacy, make sure they’re in the preferred network. Out-of-network pharmacies can charge you double.

Check Your Pharmacy Network - Don’t Assume It’s the Same

In 2024, 78% of Medicare Advantage plans changed their provider networks. That includes pharmacies. You might have been paying $15 for your blood pressure pill at your neighborhood CVS last year. This year? CVS is no longer in-network. Now you have to drive 12 miles to a different pharmacy - and pay $45.

Use the Plan Finder tool to search for your pharmacy by name. If it’s not listed as preferred, you’re paying more. Some plans even have tiered networks: Preferred, Standard, and Out-of-Network. Preferred pharmacies give you the lowest cost. Standard? Higher. Out-of-network? You might pay full retail price.

If your pharmacy is dropping out, find out which other pharmacies are preferred. Call them. Ask if they can fill your prescriptions. Some offer mail-order options with free shipping - which could save you even more.

Watch for the New $35 Insulin Cap and the End of the Donut Hole

Thanks to the Inflation Reduction Act, 2025 is a turning point for medication costs. The infamous "donut hole" - the coverage gap where you paid full price after hitting your deductible - is now gone. You’ll never pay more than 25% of the cost for brand-name drugs in the catastrophic phase.

And insulin? You pay no more than $35 per month for each prescription, no matter what plan you’re on. This applies to all Medicare Part D and Medicare Advantage plans. But here’s the catch: not every plan automatically applies this cap. Make sure your plan lists insulin as a covered drug at the $35 cap. If it doesn’t, switch.

Same goes for other high-cost drugs. The law now caps out-of-pocket spending for certain medications at $2,000 per year starting in 2025. But this only applies if your plan complies. Double-check that your plan includes these protections.

Don’t Forget the Extras - And the Traps

Many Medicare Advantage plans offer extra benefits: dental, vision, hearing aids, gym memberships, even transportation to appointments. Sounds great - until you read the fine print.

Some plans offer $500 for dental, but only if you haven’t had a cleaning in the last two years. Others give you free hearing aids - but only if you buy them from their contracted vendor. Some supplemental benefits are only available to people with certain chronic conditions. If you’re dual-eligible (Medicare + Medicaid), 31% of Advantage plans have hidden eligibility rules that aren’t shown on the Plan Finder.

Ask yourself: Do you really need that gym membership if you can’t get to it? Is that $100 dental benefit worth it if you have to pay $150 just to get a cleaning? Focus on benefits that actually save you money on medications or health care - not extras you’ll never use.

When to Switch - And When to Stay

You don’t have to switch plans just because you can. If your current plan still covers all your meds at low cost, has your preferred pharmacy, and your doctor is still in-network - stick with it.

But if you’ve added a new medication, stopped one, or your pharmacy changed, it’s time to compare. The average beneficiary who actively compares plans saves $532 a year on prescriptions alone, according to Justice in Aging’s 2025 analysis. Some save over $1,200.

One woman in Florida switched from a $117/month Part D plan to a $21/month plan after discovering her two maintenance drugs were on Tier 2 in the new plan - not Tier 4. Her annual drug cost dropped from $1,800 to $450. She didn’t change doctors. She didn’t change pharmacies. She just looked.

What If You Miss the Deadline?

If you miss December 7, you’re locked in until next year - unless you qualify for a Special Enrollment Period (SEP). SEPs are rare. They’re for things like moving out of your plan’s service area, losing employer coverage, or qualifying for Medicaid. If you just forgot? Tough luck.

There’s a one-time window from January 1 to March 31 called the Medicare Advantage Open Enrollment Period (MAOEP). But this only lets you switch from one Medicare Advantage plan to another - or go back to Original Medicare. You can’t change your Part D plan during this time.

Bottom line: Don’t wait. Set a calendar reminder for October 1. Start gathering your meds. Review your ANOC by October 15. Use the Plan Finder by October 20. Make your decision by December 1. You’ll thank yourself in January.

Need Help? Free Counselors Are Waiting

You don’t have to do this alone. Every state has a State Health Insurance Assistance Program (SHIP). These are free, local counselors trained by Medicare. They don’t sell plans. They don’t get paid by insurers. They just help you understand your options.

Call 1-800-MEDICARE (1-800-633-4227) or visit shiptacenter.org to find your local counselor. In 2024, 68% of people who used SHIP found a better plan. And they did it without paying a dime.