How to Check Drug Coverage Tiers and Formulary Changes for Senior Medications

Every year, thousands of seniors face surprise increases in their medication costs-not because prices went up, but because their insurance plan changed where their drug sits on the formulary. If you’re on Medicare Part D or a private plan with drug coverage, you need to know how to check your drug’s tier and track changes before they hit your wallet. It’s not complicated, but if you don’t check, you could be paying $50 more a month for a pill you’ve taken for years.

What Is a Drug Formulary and Why Does It Matter?

A drug formulary is just a list of medications your insurance plan covers. But it’s not just a simple list-it’s broken into tiers. Each tier has a different cost to you. The lower the tier, the less you pay. The higher the tier, the more you pay out of pocket.

Most plans use either a 3-tier, 4-tier, or 5-tier system. Here’s how they usually break down:

• Tier 1: Preferred generics. These are the cheapest. You might pay $5 or less per prescription.
• Tier 2: Non-preferred generics or lower-cost brand-name drugs. Expect $10-$20.
• Tier 3: Higher-cost brand-name drugs with generic alternatives. Copays often jump to $30-$50.
• Tier 4: Non-preferred brand-name drugs without generics. These can cost $60 or more.
• Tier 5: Specialty drugs. These are high-cost medications like injectables, cancer treatments, or newer weight loss drugs like Wegovy or Ozempic. Costs can be $100-$500 a month.

Here’s the catch: the same drug can be in different tiers across different plans. For example, metformin (a common diabetes drug) might be Tier 1 with one insurer and Tier 2 with another. That’s why checking your specific plan matters more than general advice.

How to Find Your Plan’s Formulary

You can’t guess your drug’s tier-you have to look it up. Every Medicare Part D plan and most private insurers offer a free online formulary search tool. Here’s how to find it:

1. Go to your plan’s official website (like Humana, Cigna, or Excellus BCBS).
2. Look for a link labeled “Drug List,” “Formulary,” or “Find a Drug.”
3. Enter the exact name of your medication-use the brand name if you’re unsure of the generic.
4. Check the tier and your estimated cost (copay or coinsurance).

Some plans, like UnitedHealthcare, make this easy with a clean search interface. Others are clunky. If you’re stuck, call customer service. They’re required to help you. You can also use Medicare.gov’s Plan Finder tool to compare multiple plans at once.

Pro tip: Always check the formulary after you enroll or renew your plan. Plans update their lists every January 1st. But changes can happen anytime.

When Formularies Change (And How You’ll Know)

Plans can change their formularies during the year-not just at renewal. They might move a drug to a higher tier, remove it entirely, or add new restrictions like prior authorization.

Here’s what triggers a change:

• A new generic version becomes available (and the plan wants to save money).
• New safety data emerges about a drug.
• A drug gets pulled from the market.
• Costs for a drug spike unexpectedly.

By law, your plan must notify you 60 days in advance if they’re removing a drug or adding new restrictions. But if they’re just moving it to a higher tier, they only need to tell you in their annual notice-usually mailed in October.

That’s the problem. Most people throw that letter away. Don’t. Open it. Look for your medications.

And here’s something even fewer people know: if your drug is changed mid-year and you’re already taking it, your plan must let you keep it for at least 30 days. That’s called a “transition policy.” Use that time to talk to your doctor about alternatives or file an exception.

What to Do If Your Drug Moves to a Higher Tier

If your blood pressure pill, diabetes med, or cholesterol drug suddenly jumps from $10 to $50 a month, you’re not stuck. You have options.

1. Ask your doctor for a generic alternative. Many brand-name drugs have cheaper generic versions that work just as well. For example, lisinopril is the generic for Zestril and Prinivil.
2. Request a formulary exception. You can ask your plan to cover your drug at a lower tier if it’s medically necessary. Your doctor fills out a short form explaining why you need it. Approval rates range from 55% to 82%, depending on your plan and how strong the medical reason is.
3. Use a 30-day transition supply. If your drug was removed or moved, you can get one more 30-day refill at the old cost. Use that time to switch or appeal.
4. Check GoodRx or SingleCare. Sometimes, the cash price at your pharmacy is cheaper than your copay-even on Tier 5. These apps show real-time prices at local pharmacies.

One senior in Michigan told her pharmacist she couldn’t afford her new $65 copay for her heart medication. The pharmacist found a similar drug on Tier 2. Her new copay: $12. She didn’t need to file an exception. She just needed someone to look.

Why GLP-1 Weight Loss Drugs Are Changing Everything

In 2025, the biggest formulary shift is happening with weight loss drugs like Wegovy, Ozempic, and Mounjaro. These drugs are now among the most prescribed for seniors, especially those with diabetes or obesity.

But here’s the problem: most plans now put them in Tier 5. That means you could pay $1,000 a month out of pocket-unless you get an exception.

Insurance companies say they’re doing this because the drugs are expensive. But experts say they’re also trying to limit use since these drugs aren’t yet approved for weight loss in Medicare Part D. That’s a gray area. Many seniors are being denied coverage-even though they’re using them for diabetes, which is covered.

If you’re on one of these drugs, check your formulary now. If it’s in Tier 5, ask your doctor to submit an exception based on your medical need-not just weight loss. Many approvals are granted when the reason is “type 2 diabetes management.”

Who Can Help You Navigate This?

You don’t have to figure this out alone.

• SHIP (State Health Insurance Assistance Program): Free, local counselors who help seniors understand Medicare. They helped 1.7 million people in 2022.
• Your pharmacist: Pharmacists know formularies inside and out. Ask them if there’s a cheaper alternative.
• Your doctor: Don’t be afraid to say, “This drug just got a lot more expensive. Can we switch?”
• Medicare Rights Center: Offers free advice on formulary exceptions and appeals.

Don’t wait until you’re at the pharmacy counter with a $100 bill. Check your formulary every fall, before open enrollment. Make a list of your meds. Keep a copy. Update it every time you get a new plan notice.

Common Mistakes Seniors Make

Here’s what trips people up:

• Thinking “my plan covers it” means “it’s cheap.” Coverage doesn’t equal affordability.
• Not checking after plan renewal. Changes happen every January.
• Assuming the same drug is in the same tier across plans. It’s not.
• Not asking for exceptions. 31% of people who need them don’t apply.
• Ignoring pharmacy cash prices. Sometimes, paying cash is cheaper than using insurance.

One man in Florida kept paying $45 a month for his cholesterol drug. He finally checked GoodRx and found the same pill for $12 at Walmart. He stopped using insurance for it. He saved $396 a year.

What’s Coming in 2025-2026

The government is pushing for simpler formularies. By 2025, Medicare may standardize on a 4-tier system across all Part D plans. That could make things easier. But it also means more drugs could move into higher tiers as plans try to control costs.

Also, 78% of insurers plan to use AI tools by 2025 to recommend cheaper alternatives to patients. That’s good-if the system works. But right now, many seniors still get lost in the process.

Bottom line: the system isn’t broken. But it’s designed to save insurers money-not to make life easy for you. The only way to protect yourself is to stay informed.

If you take even one prescription regularly, checking your formulary isn’t optional-it’s essential. A 15-minute search every fall can save you hundreds, or even thousands, a year. Don’t wait until the pharmacy tells you your copay jumped. Be the one who finds out first.