How to Check Drug Coverage Tiers and Formulary Changes for Medicare Part D

Every year, thousands of seniors face surprise increases in their medication costs-not because prices went up, but because their insurance plan quietly moved their drug to a higher tier. If you're on Medicare Part D or a private plan with a formulary, you need to know how to check your drug coverage before filling each prescription. This isn't optional. It's the difference between paying $10 or $60 for the same pill.

What Is a Drug Formulary and Why Does It Matter?

A drug formulary is simply the list of medications your insurance plan covers. But it’s not just a list. It’s broken into tiers, and each tier determines how much you pay out of pocket. Tier 1 usually means the lowest cost. Tier 5? That’s where specialty drugs like weight loss injections or cancer treatments land-and those can cost hundreds per month.

Medicare Part D plans have to cover at least two drugs in every therapeutic category. That sounds fair, right? But here’s the catch: the same drug can be in Tier 1 with one plan and Tier 3 with another. For example, metformin, a common diabetes drug, might cost $5 with one insurer but $20 with another, depending on where it’s placed. That’s why checking your formulary isn’t a one-time task. It’s an annual habit.

How Formulary Tiers Work (And How They Change)

Most plans use either a 3-tier, 4-tier, or 5-tier system. Here’s what you’ll typically see:

• Tier 1: Preferred generics. These are the cheapest. Think $5-$10 per prescription.
• Tier 2: Non-preferred generics or lower-cost brand-name drugs. Usually $15-$30.
• Tier 3: Higher-cost brand-name drugs with generic alternatives available. Often $40-$70.
• Tier 4: Non-preferred brand-name drugs with no cheap alternative. Can be $80 or more.
• Tier 5: Specialty drugs. These include GLP-1 medications like Wegovy or Ozempic, injectables, and complex treatments. Costs range from $100 to $1,000+ per month.

Changes happen all the time. When a new generic hits the market, insurers often move the brand-name version up a tier to push people toward the cheaper option. That’s legal-and common. In 2023, about 17% of formulary changes involved moving drugs to higher tiers, according to Avalere Health. That means if your blood pressure pill was in Tier 1 last year, it might be in Tier 3 this year. And you won’t know unless you check.

How to Check Your Drug’s Tier (Step by Step)

You don’t need to be a tech expert. Here’s how to do it in under 10 minutes:

1. Find your plan’s formulary tool. Go to your insurance provider’s website. Look for “Drug List,” “Formulary,” or “Find a Drug.” Most plans, like Cigna, Humana, or Excellus BCBS, have a search bar right on the homepage.
2. Enter your exact drug name. Use the brand name if you’re unsure. For example, type “Lisinopril” instead of “high blood pressure pill.”
3. Check the tier and cost. The tool will show you the tier (1-5) and your copay or coinsurance. Look for “preferred” or “non-preferred” labels-those matter.
4. Compare alternatives. If your drug is in a high tier, the tool will often suggest lower-cost alternatives in the same class. Ask your pharmacist: “Is there another drug like this that’s cheaper on my plan?”
5. Save the page. Take a screenshot or print it. You’ll need it if you need to file an exception later.

Pro tip: Don’t wait until you’re at the pharmacy. Do this before your prescription renews. Most formularies update on January 1st, but changes can happen anytime.

When Your Drug Gets Moved to a Higher Tier

If your drug suddenly costs more, you’re not alone. In Q3 2023, 42% of customer service calls to Simply Prescriptions were about unexpected tier changes. But you have rights.

First, check your mail. By law, your plan must send you a written notice if they’re changing your drug’s tier or removing it entirely. The notice must say when the change takes effect and tell you how to request an exception.

Next, talk to your doctor. You can ask them to file a formulary exception request. This is a formal request asking your plan to cover your drug at a lower tier because:

• The alternative drugs didn’t work for you
• You have side effects from other drugs in the same class
• Your condition requires this specific medication

In 2022, about 1.2 million exception requests were filed. Approval rates ranged from 55% to 82%, depending on your plan and how strong your medical justification was. One Medicare member in Melbourne shared: “My doctor wrote a letter explaining why I couldn’t switch from my current statin. My plan approved it-and kept my cost at $10.”

What to Do If You Can’t Get an Exception

Sometimes, your request gets denied. That’s frustrating-but not the end. Here’s what to try next:

• Ask your pharmacist for a 30-day supply. Many plans offer a transition supply if your drug was previously covered. This gives you time to switch or appeal.
• Use GoodRx or SingleCare. These discount cards often beat your plan’s copay, even on Tier 5 drugs. Sometimes, the cash price is lower than your insurance rate.
• Switch plans during Open Enrollment. If your drug keeps moving up tiers, it might be time to change plans. Use Medicare.gov’s Plan Finder tool to compare formularies side by side.

Red Flags That Your Formulary Is Hard to Navigate

Not all plans make this easy. Watch out for:

• No online formulary tool (or it’s broken)
• Formulary PDFs that are 50 pages long with tiny print
• Customer service can’t tell you your drug’s tier without your member ID and date of birth
• No clear explanation of what “preferred” means

In 2023, UnitedHealthcare scored 4.2 out of 5 for formulary clarity. Smaller regional plans? Only 2.8. If your plan feels like a maze, reach out to your State Health Insurance Assistance Program (SHIP). They offer free, local help-no cost, no sales pitch. In 2022, SHIP helped over 1.7 million people understand their drug coverage.

What’s Changing in 2025 and Beyond

The biggest trend? GLP-1 weight loss drugs like Wegovy and Ozempic are being moved into the highest tiers. FepBlue admitted in September 2023 that some 2026 formularies still list these drugs incorrectly. That means even if you’re covered now, your cost could jump next year.

CMS is pushing for simpler, standardized tiers. By 2025, they’re piloting a uniform 4-tier model across Medicare Part D plans. That’s good news. Right now, the lack of standardization is confusing. A 2022 survey found 68% of Medicare beneficiaries didn’t understand their formulary tiers-and that confusion led to skipped doses and hospital visits.

Future plans will use AI to recommend lower-cost alternatives based on your history. By 2025, 78% of insurers plan to roll out these tools. But until then, you’re still the best advocate for your own care.

Final Checklist: Your Annual Formulary Review

Do this every October, before Open Enrollment ends:

• Write down every drug you take, including over-the-counter ones your doctor recommended
• Check each one’s tier and cost on your plan’s website
• Compare your plan’s formulary to other plans using Medicare.gov’s Plan Finder
• Call your pharmacist and ask: “Is there a cheaper drug that works the same way?”
• Save your formulary page. Print it or screenshot it. You’ll need it next year.

If you don’t check your formulary, you’re gambling with your health-and your wallet. Don’t wait for a surprise bill. Take five minutes now. It could save you hundreds.

Next Steps: What to Do Right Now

If you’re on Medicare Part D or any prescription drug plan:

• Go to your plan’s website and search for your top three medications.
• Write down the tier and copay for each.
• If any cost more than $20, ask your pharmacist about alternatives.
• If you’re unsure, call your State Health Insurance Assistance Program (SHIP). They’re free, local, and don’t sell anything.

Don’t wait for your next pharmacy bill. Check today. One quick search could save you hundreds-or even thousands-over the next year.