What Medicare Part D Changes Should You Look for During AEP?
Your Medicare prescription drug coverage can change from one year to the next, even if you stay with the same plan. A medication that was affordable this year could have a different cost next year. A preferred pharmacy could have different cost-sharing. A drug could move to another tier, or a plan could change its formulary.
That's why reviewing your Part D coverage during the Medicare Annual Enrollment Period (AEP) is so important.
The 2026 AEP runs from October 15 through December 7, 2026, and changes made during this period generally take effect January 1, 2027. Medicare beneficiaries can use this period to review and change their Medicare prescription drug coverage when eligible.
The 2027 plan year is also particularly important because several Medicare Part D changes are already established for 2027. CMS released preliminary 2027 Part D bid information on July 28, 2026, and final plan offerings and premiums are expected to become available in September.
For a broader explanation of AEP dates and enrollment options, see our The Medicare Annual Enrollment Period (AEP): What You Need to Know Before October 15.
Why You Should Review Part D Every Year
It can be tempting to assume that your prescription coverage will remain the same if you don't change plans.
However, Medicare drug plans can change their premiums, deductibles, formularies, pharmacy networks, and cost-sharing requirements.
Medicare explains that every Part D plan has its own formulary, or list of covered prescription drugs. Plans can also place medications into different tiers, which can affect how much you pay.
This means that simply checking whether your medications are listed isn't enough.
You should also look at how each medication is covered and what you may pay for it during the upcoming year.
A yearly review can help you identify changes before they affect your pharmacy bill.
Start With Your Annual Notice of Change
If you have a Medicare Advantage plan with prescription drug coverage or a standalone Part D plan, one of the first documents to review is your Annual Notice of Change (ANOC).
Your ANOC explains important changes to your plan that will take effect in the new year.
Belle Vida's ANOC Letter resource highlights several areas beneficiaries should review, including deductible changes, premium changes, copayments and coinsurance, formulary changes, and physician or pharmacy network changes.
Don't just look at the first page and put the document away.
Compare the changes with the medications and pharmacies you actually use.
If your plan's prescription costs are changing, that could be more significant to you than a small change in the monthly premium.
Check Whether Your Medications Are Still Covered
Your medication list should be at the center of your Part D review.
Write down every prescription you currently take, including the medication name, dosage, and frequency.
Then check each drug against the plan's 2027 formulary once the new plan information becomes available.
Medicare notes that each drug plan has its own formulary, although plans must cover a broad range of medications and must include most drugs in certain protected classes.
Don't assume that because a drug was covered in 2026 it will have exactly the same coverage in 2027.
Formularies can change according to Medicare's rules. A plan may also change the tier assigned to a medication, which can affect your cost-sharing.
If you discover that a medication is no longer covered or has become significantly more expensive, investigate your alternatives before deciding to keep your current plan.
Pay Attention to Drug Tiers
Knowing that a medication is covered is only part of the equation.
Medicare Part D plans generally place covered medications into different tiers. Lower tiers typically have lower cost-sharing, while higher tiers can result in greater costs.
For example, a generic medication may be placed on a lower tier than a preferred or non-preferred brand-name drug.
When comparing plans, don't just ask:
"Is my medication covered?"
Also ask:
"What tier is my medication on, and what will I pay?"
A medication that remains covered but moves to a higher tier could affect your annual prescription expenses.
This is especially important if you take several medications regularly.
Check for Prior Authorization and Other Restrictions
Some prescription drugs have additional coverage requirements.
A Part D plan may use tools such as prior authorization, step therapy, or quantity limits to manage prescription drug coverage.
Medicare explains that these types of rules can affect how a plan covers particular medications.
For example, prior authorization may require your prescriber to provide additional information before the plan covers a medication.
Step therapy may require you to try another medication first.
Quantity limits can restrict how much of a medication the plan will cover within a certain period.
If your current medication has one of these requirements, check whether the rule will remain the same for 2027.
Compare Your Pharmacy Options
Your prescription costs don't depend only on the medication.
Where you fill your prescriptions can also matter.
Part D plans have pharmacy networks, and some pharmacies may offer preferred cost-sharing under particular plans.
Medicare recommends considering pharmacy options when comparing Part D coverage.
If you've been using the same pharmacy for years, don't automatically assume it will provide the same pricing under every plan.
Check whether your pharmacy is considered preferred, in-network, or out-of-network under the plan you're considering.
You can also compare mail-order options if they are available and convenient for your medications.
Review Your Deductible and Other Drug Costs
Your Part D premium is only one part of what you may spend on prescriptions.
Depending on the plan, you may also have a deductible, copayments, or coinsurance.
For 2026, Medicare states that no Part D plan may have a deductible above $615, although some plans have lower deductibles or no deductible.
The amount you pay in 2027 will depend on the new plan year's rules and the specific plan you choose.
That's why you shouldn't compare plans based solely on their monthly premiums.
A plan with a slightly higher premium could potentially result in lower overall prescription costs depending on your medications and pharmacy.
When comparing plans, consider the total estimated cost of your medications, not just the premium.
Understand the Part D Out-of-Pocket Protection
Medicare Part D has undergone significant changes under the Inflation Reduction Act.
Beginning in 2025, the Part D benefit eliminated the coverage gap, and beneficiary cost-sharing in the catastrophic phase was eliminated beginning in 2024. CMS is codifying these changes for 2027 and beyond.
For 2026, Medicare lists a $2,100 annual out-of-pocket limit for covered Part D prescription drugs.
The specific limit and plan details for 2027 should be reviewed once the official plan information becomes available.
This protection can be especially important for people who take expensive medications or have significant prescription drug needs.
Even with an out-of-pocket limit, however, your monthly premium and other healthcare expenses may still apply separately.
The Medicare Prescription Payment Plan May Be Worth Reviewing
Medicare also offers the Medicare Prescription Payment Plan, which allows eligible beneficiaries to spread their Part D out-of-pocket prescription costs across the calendar year instead of paying the full amount at the pharmacy when prescriptions are filled.
Importantly, the payment plan does not reduce the total amount you owe. It changes when you pay it.
If you expect high prescription expenses, ask your plan whether participating could make your payments easier to manage.
However, compare the payment schedule with your budget before deciding whether to participate.
Look at the 2027 Part D Changes
The 2027 plan year includes several developments that make this year's AEP review particularly important.
CMS's Contract Year 2027 final rule codifies major Part D changes from the Inflation Reduction Act, including the elimination of the coverage gap phase, the reduced annual out-of-pocket threshold, and the removal of cost-sharing in the catastrophic phase.
CMS also finalized updates to the Part D risk-adjustment model and other policies affecting how Part D plans operate.
For beneficiaries, these policy changes don't mean every plan will have identical premiums or drug costs.
Your individual plan still matters.
That is why the most useful question during AEP isn't simply "What changed with Medicare Part D?"
It's:
"How do the 2027 changes and my plan's new rules affect the prescriptions I actually take?"
2027 Part D Premium Information Has Already Been Released
CMS released preliminary 2027 Part D bid information on July 28, 2026.
According to CMS, the 2027 national average monthly bid amount is $296.05, while the 2027 national base beneficiary premium is $41.33. The base beneficiary premium is a statutory figure used in calculating plan-specific basic Part D premiums; it is not the amount every beneficiary will pay.
CMS also stated that final 2027 Medicare Advantage and Part D plan offerings and premiums are expected to be released in September once plan offerings are finalized.
This is an important distinction.
The national figures provide information about the overall Medicare program, but they do not tell you what your specific Part D plan will cost in 2027.
Your plan's own premium, deductible, formulary, pharmacy network, and cost-sharing information should be reviewed once the official plan materials are available.
Review Medicare Drug Price Negotiation Changes
Another development to watch is Medicare's Drug Price Negotiation Program.
For the first group of negotiated drugs, negotiated prices took effect January 1, 2026. CMS has also established negotiated prices for the program's 2027 initial price applicability year. Those prices are scheduled to take effect January 1, 2027.
If you take a medication included in the negotiation program, it's worth checking how the negotiated price and your Part D plan's coverage interact.
However, don't assume that a negotiated Medicare price automatically means your personal prescription cost will fall by a specific amount.
Your plan's benefit design, formulary placement, pharmacy, and applicable cost-sharing rules can still matter.
Compare Your Estimated Annual Drug Costs
Once 2027 plan information becomes available, use Medicare's official Plan Compare tool to enter your medications and preferred pharmacies.
Medicare's comparison tool allows beneficiaries to enter their drugs and pharmacies and compare available plan costs.
This is more useful than simply comparing premiums.
Suppose Plan A has a lower monthly premium but places several of your prescriptions on higher-cost tiers. Plan B might have a slightly higher premium but offer lower prescription costs for the medications you actually take.
Your personalized comparison could therefore look very different from a general advertisement.
When possible, compare your estimated annual drug costs rather than focusing on the premium alone.
Don't Forget Your Preferred Pharmacy
A medication can be covered by a Part D plan while still costing you different amounts depending on the pharmacy you use.
Before selecting a plan, enter your preferred pharmacy into Medicare's plan comparison tool.
If you use more than one pharmacy, compare them as well.
For people who rely on mail-order prescriptions, check whether mail-order services are available and how their pricing compares with retail options.
These details may seem minor, but they can make a meaningful difference over the course of a year.
What If Your Medication Is No Longer Covered?
Finding out that a medication isn't on your plan's formulary can be concerning, but it doesn't necessarily mean you have no options.
Medicare explains that if you or your prescriber believe none of the covered drugs will work for your condition, you can request a formulary exception. The prescriber generally needs to provide supporting information explaining the medical reason for the exception.
You can also talk with your healthcare provider about whether another covered medication may be medically appropriate.
The important thing is not to stop taking a prescribed medication simply because your plan has changed its formulary.
Discuss any coverage problem with your healthcare provider and insurance plan so you can understand your options.
A Simple Part D Review Checklist
Before choosing or keeping your Part D coverage for 2027, review:
Your medications: Are they still covered?
Drug tiers: What tier is each medication in?
Restrictions: Are prior authorization, step therapy, or quantity limits required?
Pharmacy: Is your preferred pharmacy in-network or preferred?
Premium: What will you pay each month?
Deductible: How much will you pay before coverage begins?
Copayments and coinsurance: What will your share be for each medication?
Annual drug costs: What is your estimated total for the year?
Out-of-pocket protection: How does the plan handle high prescription expenses?
Plan changes: What does your Annual Notice of Change say about 2027?
Reviewing these items together gives you a much clearer picture than looking at any single number.
When Should You Start Reviewing Part D?
You don't need to wait until October 15 to start gathering information.
Medicare's 2026 handbook identifies October 1, 2026 as the date beneficiaries can begin comparing current coverage with options for 2027 before Open Enrollment begins.
However, you can prepare before then.
Start by making an updated medication list and noting your preferred pharmacies. Review your current plan's coverage and watch for your Annual Notice of Change.
Once the 2027 plan information is available, use Medicare's comparison tools to evaluate your options.
This approach gives you time to investigate questions rather than trying to make a decision at the end of AEP.
Conclusion
Medicare Part D deserves careful attention during the Annual Enrollment Period because prescription coverage can change from year to year.
For the 2026 AEP, which runs October 15 through December 7, 2026, beneficiaries choosing coverage for 2027 should look closely at their formularies, drug tiers, pharmacy networks, premiums, deductibles, cost-sharing, coverage restrictions, and estimated annual prescription costs.
The 2027 plan year also brings important developments tied to the Inflation Reduction Act and Medicare's ongoing prescription drug reforms. CMS has already released preliminary 2027 Part D bid information, while final plan offerings and premiums are expected later in September.
Don't assume your prescription coverage will stay the same simply because you stay with the same plan.
Take the time to review what you're taking, where you fill your prescriptions, and how much your medications are likely to cost under your 2027 options.
A careful Part D review during AEP can help you avoid unpleasant surprises when your new coverage begins in January.
Your prescription list may be the most important document to bring to your Medicare plan review this AEP.
Make Your Medicare Prescription Coverage Work for You
Reviewing Part D coverage doesn't have to be overwhelming. Looking at your medications, pharmacies, and expected costs before making a decision can help you approach AEP with greater confidence.
If you have questions about Medicare Part D, Medicare Advantage, or your coverage options, schedule a consultation.
For more educational information about Medicare and health insurance, visit Belle Vida Insurance.