Every fall, insurance companies quietly update the “map” of which medications they cover in their health plans.

This map is your drug formulary, and it can change every single year. Sometimes your prescription stay exactly where they are. Other times they move to a higher tier, or they may not be covered at all.

What some people do not realize is if they stay in the same plan for the next year, without checking the formulary, they might be in for a surprise when they fill their prescriptions in January. Your medications could have moved to another tier or may not be covered. You could have to pay out of pocket.

This isn’t meant to scare you . It is meant to keep you informed and save you money. Here’s why it happens and how to protect yourself.

Why Formularies Change Every Year

A formulary is simply the list of medications your health plan covers, often organized by tiers like generic, preferred brand, non-preferred brand, and specialty drugs.

Whether Medicare Part D, Medicare Advantage plan, ACA Marketplace, or employer coverage,  formularies change each year because;

• New drugs and generics enter the market
• Safety guidelines and treatment recommendations evolve
• Drug manufacturers change pricing and rebates
• Plans adjust benefits to manage rising costs (especially high-cost drugs like GLP-1 medications)

Medicare has always allowed drug plans to update their formularies within set guidelines. The point is to keep coverage up to date — but it also means your coverage isn’t guaranteed to stay the same year after year. [Medicare]

Independent advisors who work with Medicare plans emphasize the practical result and stress the importance of an annual review.

Formularies change yearly. Even if a drug is covered this year, it may not be next year. One more reason an annual review is so important. [Clear Benefits Advisors]

And it’s not just a Medicare issue. In employer plans, brand-name drug prices are reviewed and renegotiated every year, which means what a plan covers, and at what tier, can shift from one plan year to the next. [Blue Cross and Blue Shield]

Why This Matters: Real People, Real Budgets

This isn’t a theoretical exercise. Prescription drugs are part of everyday life in the U.S.:

About two thirds of U.S. adults, more than 131 million people, use prescription medications. Almost half of Americans say  it is hard to afford health care costs, including prescriptions. Drug prices, especially for people on multiple medications, continue to be a major stress point for families, retirees, and small business owners. [Health Policy Institute]

A 2025 KFF report shows almost half of U.S. adults say it’s difficult to afford health care costs overall, and about 1 in 4 had problems paying medical or drug bills in the last 12 months. [KFF]

Meanwhile, employers are feeling the squeeze too:

In 2025, the average annual family premium for employer coverage rose to about $27,000, with prescription drugs, especially GLP-1 weight-loss medications, named as a major driver of rising costs. [Reuters]

When health plans react to these rising pressures, one of the first adjustments to make is to the formulary. That’s why a medication can move to a higher tier or lose coverage entirely, even when you have not changed anything.

How Your Drug Can Change, Even If You Don’t

Here are the changes we see each year:

1. Same drug, new tier
   Your medication is still covered, but it’s moved from a lower-cost tier (for example, Tier 2) to a higher-cost tier (Tier 3 or specialty). That can mean higher copays or coinsurance for the exact same prescription.
2. Prior authorization, step therapy, or quantity limits added
   The plan may now require your doctor to get approval first. You are asked to try a lower-cost alternative, or they have strict quantity limits.  These are ways plans control spending.
3. Drug removed from the formulary
   Sometimes a plan removes a medication with a generic or similar alternative. Medicare does allow certain “negative formulary changes” but plans must follow specific rules.  [Medicare Interactive]
   

For people with stable prescriptions, these behind-the-scenes changes can feel like the rug has been pulled out from under them—especially when they find out at the pharmacy counter instead of during open enrollment.

You’re Not Powerless: Practical Solutions

Here’s how to protect yourself, your family, and your employees.

For Individuals & Medicare Beneficiaries

1. Make an Annual “Medication Checkup”

Once a year – preferably before or during AEP Medicare’s Annual Enrollment Period (Oct 15–Dec 7) or your employer/ACA open enrollment create a simple, up-to-date list:

• All your prescriptions
• Dosage
• How often you take them
• Your preferred Pharmacy
• Any important over-the-counter medications

This becomes your starting point for comparing plans.

Many Medicare resources and advisors stress that annual plan review is more essential than ever because premiums, formularies, and cost-sharing can change significantly year to year. [Solace Health]

2. Review the Formulary Before You Re-Enroll

Don’t assume:

“If it worked last year, it’ll work next year.”

Look up each medication in each plan’s formulary and check:

•  Is it covered?
• What tier is it?
• Any prior authorizations or step therapy required?
• Any quantity limits?

If something changed, that’s your signal to look at other plan options.

3. Ask About Alternatives Before You Panic

If a medication becomes too expensive:

Talk to your provider about:

• Generic
• Therapeutic equivalents
• Adjusting the prescription

A small medical adjustment can sometimes bring your the cost down significantly.

4. Use Exceptions, Appeals & Assistance Programs

You have rights. You can request:

• Exception ( to cover a non formulary drug)
• Tiering exceptions (to treat your drug as a lower tier)
• Appeals if the plan denies your request
• Transition fills:  in certain cases  [CMS]

There are charitable programs ans manufacturing savings for some people.

5. Work with an Independent Advisor

This is exactly where a firm like National Benefit Plans, Inc supports you. We:

• Compare plans
• Look up your medications
• Explain cost differences
• Help you change plans if needed

A 15-minute review can prevent a year of unexpected pharmacy bills.

For Small Business Owners & HR Leaders

Formulary changes affect more than individual members – they affect your organization’s costs and your employee’s health.

1. Build a Prescription Review into Your Annual Benefits Calendar

Employer benefits experts recommend an annual review of your prescription drug coverage, not just medical premiums. That review should look at utilization trends, the drug mix, and cost drivers—and identify where the formulary is helping or hurting your people. [SBMA Benefits]

Review not only medical premiums, but also:

1. The drug mix
2. High–cost categories
3. Employee affordability issues
4. Changes in employer liability

2. Prepare for High-Cost Drug Categories

GLP-1 medications and specialty drugs are reshaping employer budgets.

Survey data shows large employers increasingly offer coverage for these drugs, but many report they’ve had significant impact on prescription drug spending and premium growth. [BioXconomy]

You don’t have to cover everything for everyone. But you do a plan:

1. Which drugs will be covered
2. Clinical criteria
3. Prior authorization rules
4. Communication strategy for employees

3. Prioritize Transparency & Communication

A sudden formulary changes often feel like a “gotcha.”  To prevent frustration:

• Share plain-language summaries
• Host open enrollment sessions that explain drug coverage
• Encourage 1:1 reviews for employees with ongoing conditions

This builds trust and helps employees stay compliant with their medications.

The Bottom Line: Don’t Let Formularies Happen To You

You can’t stop plans from updating their formularies, but you can prevent surprises.

Here’s what you control:

• Keeping an updated medication list
• Checking the formulary before you re-enroll
• Exploring alternatives if a drug changes
• Using exceptions and appeals when needed
• Getting expert help so you are not navigating this alone

At National Benefit Plans Inc, this is the kind of behind-the-scenes support we provide every day. If your prescriptions are a big part of your health—and your budget—it’s worth having someone in your corner.