Every year, millions of Medicare beneficiaries miss out on hundreds - sometimes over a thousand - dollars in savings on their medications. Why? Because they don’t review their coverage during the Annual Open Enrollment Period. If you take regular prescriptions, skipping this window could mean paying more for your insulin, blood pressure pills, or arthritis meds next year than you did this year - even if your health hasn’t changed at all.
Know the Dates - and Stick to Them
The window to change your Medicare drug coverage is short: October 15 to December 7 every year. That’s it. Changes you make during this time take effect on January 1. Miss December 7, and you’re stuck with your current plan until next October. No do-overs. No exceptions. For 2026 coverage, the window is October 15, 2025, through December 7, 2025. CMS, the agency that runs Medicare, sets these dates. They don’t move. And if you’re on a Medicare Advantage plan that includes drug coverage, you’re still bound by this same window - unless you’re switching back to Original Medicare, which you can do during the January-March Medicare Advantage Open Enrollment Period. But that’s a one-time, limited chance. Don’t rely on it.Start With Your Medications - Not Your Premiums
Most people begin by looking at monthly premiums. That’s a mistake. A plan with a $0 premium might cost you $400 a month in out-of-pocket drug costs. Another with a $50 premium might save you $800 a year because your meds are covered better. Start by listing every medication you take. Include the exact name, dosage, and how often you take it. Don’t guess. Check your pill bottles or pharmacy records. If you take insulin, Ozempic, or other high-cost drugs, pay special attention - these are the ones most likely to shift tiers or get restricted. Then, get your current plan’s Annual Notice of Change (ANOC). It arrives in the mail between September 30 and October 15. This document tells you exactly what’s changing: which drugs are no longer covered, which ones moved to a higher tier (meaning more cost), which pharmacies are no longer preferred, and how your deductible or copay is changing. Don’t skip this. 87% of people who saved money in 2024 started here.Use the Medicare Plan Finder - Don’t Guess
Go to Medicare.gov and use the Plan Finder tool. It’s free, official, and updated daily. Type in your medications, zip code, and preferred pharmacy. The tool shows you every plan available in your area - including Medicare Advantage plans and standalone Part D plans. Look at three things:- Formulary coverage: Is every drug you take on the list? And at what tier? Tier 1 is cheapest. Tier 4 or 5? That’s specialty drug territory - often $100+ per prescription.
- Pharmacy network: Is your go-to pharmacy in-network? If it’s not, you’ll pay more. Some plans have preferred pharmacies with lower copays. Check if your pharmacy is one of them.
- Total estimated cost: The Plan Finder now calculates your projected annual drug cost based on your exact meds. This number is more important than the monthly premium.
Watch for Hidden Changes - They Cost More
Plans don’t just change prices. They change rules. Here’s what to watch for:- Step therapy: You might need to try a cheaper drug first before your doctor can prescribe yours.
- Prior authorization: Your doctor has to call the plan to get approval before you can fill your prescription.
- Quantity limits: You can only get 30 pills instead of 90 per month - forcing you to refill more often and pay more in copays.
Don’t Forget the Inflation Reduction Act Changes
Big changes happened in 2025 - and they’re still rolling out.- Insulin is capped at $35 per month. No matter what plan you’re on, if you take insulin, you pay no more than $35 for a 30-day supply. This applies to all Part D and Medicare Advantage plans.
- The donut hole is gone. The coverage gap - where you paid more out of pocket after hitting a spending limit - was fully closed in 2025. You now pay 25% coinsurance for brand-name drugs even in the catastrophic phase.
- Some vaccines are free. Shingles, flu, and pneumonia vaccines are now fully covered with no cost-sharing.
What If You’re on Medicaid Too?
If you qualify for both Medicare and Medicaid (called “dual eligible”), you have extra protections - but also more complexity. Medicaid can help pay your Medicare premiums, copays, and even cover drugs Medicare doesn’t. But not all Medicare Advantage plans offer the same supplemental benefits. 31% of Medicare Advantage plans in 2024 had supplemental benefits - like dental, vision, or transportation - but with hidden restrictions. Some only covered dental cleanings, not fillings. Others required you to use specific providers. Always read the fine print. Use the Plan Finder, then call your State Health Insurance Assistance Program (SHIP) counselor. They’re trained to spot these traps.
When to Call for Help
You don’t have to do this alone. Over 68% of people who called the Medicare Rights Helpline in 2024 needed help understanding formulary changes. That’s normal. Free, local help is available through SHIP. Every state has certified counselors - over 9,400 of them. They don’t sell plans. They don’t get paid by insurers. They answer questions. You can find your local SHIP office at shiptacenter.org or call 1-877-839-2675. If you’re overwhelmed, start here:- October 1-10: List your meds and dosages.
- October 10-15: Get your ANOC and EOC (Evidence of Coverage) from your current plan.
- October 15-20: Use Medicare Plan Finder to compare plans based on your meds.
- October 20-25: Confirm your pharmacy is still preferred.
- October 25-30: Review supplemental benefits if you need them.
- December 7: Submit your change.
What Happens If You Do Nothing?
If you don’t change anything, you’ll stay on your current plan - automatically. But that doesn’t mean it’s still the best. In 2024, 42% of plans increased cost-sharing on specialty drugs. 60% changed at least one medication’s formulary status. One man in Florida stayed on his plan because he “didn’t want to deal with it.” His blood thinner moved from Tier 2 to Tier 5. His monthly cost jumped from $48 to $312. He didn’t realize until his pharmacy told him he couldn’t fill it. Don’t be that person.Final Tip: Don’t Wait Until December
People who wait until the last week to make changes are more likely to pick the wrong plan. The Plan Finder gets busy. Phone lines get jammed. Mistakes happen. Set a reminder for October 15. Block out an hour. Do it early. You’ll have time to ask questions, compare options, and make a smart choice - not a rushed one. Your health doesn’t change overnight. But your coverage does. Make sure they match.What happens if I miss the Medicare Open Enrollment deadline?
If you miss the December 7 deadline, you’ll stay on your current plan for the entire next year. You won’t be able to switch to a different Medicare Advantage or Part D plan until the next Annual Open Enrollment Period - unless you qualify for a Special Enrollment Period (like moving out of your plan’s service area or losing other coverage). Missing the deadline can cost you hundreds or even thousands of dollars if your medications become more expensive or are no longer covered.
Can I switch Medicare Advantage plans after January 1?
Yes - but only once, and only between January 1 and March 31. This is called the Medicare Advantage Open Enrollment Period (MAOEP). During this time, you can switch from one Medicare Advantage plan to another, or drop your Advantage plan and go back to Original Medicare. But you cannot switch Part D plans during this period - only during the Annual Open Enrollment Period (October 15-December 7). This makes AEP the only time to change drug coverage without restriction.
Do I need to enroll in Part D if I have Medicare Advantage?
Not if your Medicare Advantage plan already includes prescription drug coverage - which 90% of them do in 2025. If your Advantage plan includes Part D, you don’t need a separate drug plan. But if your Advantage plan doesn’t include drug coverage (rare, but possible), you must enroll in a standalone Part D plan. Otherwise, you’ll pay full price for prescriptions and may face a late enrollment penalty if you go without creditable drug coverage for more than 63 days.
How do I know if my medication will be covered next year?
Check your current plan’s Annual Notice of Change (ANOC), which arrives between September 30 and October 15. Then use the Medicare Plan Finder tool to compare formularies across all plans in your area. Enter your exact medications and dosages. The tool shows whether each drug is covered, at what tier, and if there are any restrictions like prior authorization or step therapy. Never assume your meds will stay the same - 60% of Part D plans change at least one drug’s coverage each year.
Is there help available if I can’t afford my medications?
Yes. If you have limited income, you may qualify for Extra Help - a federal program that lowers your Part D premiums, deductibles, and copays. In 2025, the income limit is $21,870 for individuals and $29,580 for couples. You can apply through Social Security or your state Medicaid office. Even if you don’t qualify for Extra Help, the Inflation Reduction Act caps insulin at $35/month and eliminates the coverage gap. Plus, many drug manufacturers offer patient assistance programs for high-cost medications like GLP-1 drugs.