How Do You Compare Prescription Formulary Tiers?

Key Takeaways

• Don't compare tier labels alone: check what your exact medication, with its strength and form, will cost on each plan, and add up the full-year total including premiums.
• Tiers are not standardized, so the same drug can sit in Tier 2 on one plan and Tier 3 on another; always look up each drug on each plan's current formulary.
• A copay is a fixed dollar amount while coinsurance is a percentage of the drug cost, and some plans apply the deductible before tier cost-sharing, which can raise early-year costs.
• Check prior authorization, step therapy, and quantity limits for every medication, since a drug on the formulary can still require approval, a cheaper drug tried first, or a capped supply.
• Confirm your pharmacy is in-network and whether it is preferred, since copays can differ by pharmacy and mail-order may save money on monthly maintenance drugs.
• Formularies can change yearly, so reconfirm your medications' tiers and rules with the insurer during each enrollment period before choosing a plan.

Picking a health plan can feel a lot like grocery shopping with a blindfold on. The price tag looks fine, but what you'll actually pay at the pharmacy counter stays hidden. If you take a daily medicine, that surprise can add up fast.

I'm Sterling Watnem, a licensed health insurance advisor in Tampa, Florida. One question I hear often is how to compare prescription formulary tiers across plans. The short answer? Don't just compare the tier labels. Compare what your exact medicine will cost on each plan, and what rules come with it.

In this guide, I'll walk you through what a formulary is, how tiers work, and a simple step-by-step way to compare plans. If you're self-employed, between jobs, or just tired of confusing insurance jargon, this one's for you. Grab a coffee and your medication list, and let's make this easy.

What Is a Prescription Formulary?

A formulary is simply a plan's list of covered medicines. Think of it as the plan's pharmacy menu. If your drug isn't on the menu, the plan may not pay for it, or it may charge you more.

Plans often sort the drugs on that list into groups called tiers. Each tier has its own cost to you. Lower tiers usually cost less. Higher tiers usually cost more.

Here's the catch. Every plan builds its own formulary. The number of tiers, the names of the tiers, and the drugs placed in each tier can all differ. So a Tier 2 drug on one plan might be a Tier 3 drug on another. That is why comparing formulary tiers takes a little detective work.

How Do Drug Tiers Usually Work?

Many plans follow a common pattern. It's only a general guide, but it helps you picture how things are organized.

Medicare.gov describes a similar four-tier example for drug plans. But even there, it notes that actual plan setups differ. The same is true for private and Marketplace plans. A drug's tier and price can also change based on its strength, its form (like tablet versus liquid), or the pharmacy you use.

So treat the table above as a rough map, not a promise. Your plan documents are the real source of truth.

Tier vs. Copay vs. Coinsurance: What's the Difference?

These three words get mixed up a lot. Let's untangle them.

• Tier: The group a drug is placed in on the plan's formulary.
• Copay: A fixed dollar amount you pay, like $15 for a prescription.
• Coinsurance: A percentage of the drug's cost that you pay, like 30%.

The tier tells you which group a drug is in. The copay or coinsurance tells you how the plan charges you for that group. Two plans might both put your drug in Tier 2. One could charge a flat $40 copay. The other could charge 40% coinsurance. On a pricey drug, that gap could be big.

Want a deeper look at this? I break it down in Copay vs. Coinsurance: Which Costs You Less in 2026?

Why Deductibles Matter for Your Prescriptions

Here's something that trips up a lot of people. Some plans make you meet the deductible before the tier copay kicks in. That means you might pay the full cost of your medicine early in the year, even if it sits on a low tier.

Other plans skip the deductible for certain tiers, so you pay just the copay from day one. Both plans can look similar on paper. But the way you pay can be very different.

If you want to avoid common slip-ups here, take a peek at 12 Deductible Mistakes That Cost You Money in 2026.

5 Steps to Compare Prescription Formulary Tiers

Ready to do this the smart way? Here's the process I walk my clients through.

1. Build your medication list. Write down each drug's exact name, strength, dosage form, and monthly amount. "Metformin" isn't enough. You'll want "metformin 500 mg tablet, 60 per month."
2. Check each plan's current formulary. Look up every medicine on every plan you're considering. Write down the tier for each one.
3. Find the cost-sharing for that tier. Look at the plan's Summary of Benefits and Coverage. Note whether it's a copay or coinsurance, and whether the deductible applies first.
4. Check the rules on each drug. Look for prior authorization, step therapy, and quantity limits (more on these below).
5. Add up the yearly cost. Multiply your monthly drug costs by 12, then add the plan's premium. Compare the totals, not just the monthly premium.

That last step is where the real picture shows up. A plan with a lower premium can end up costing more once your prescriptions are factored in. For help weighing the big picture, see How to Compare Private Health Plans and Pick the Right One.

Watch Out for Coverage Restrictions

A drug can be on the formulary and still come with strings attached. This surprises many people. Always check for these three rules.

Prior Authorization

This means your doctor must get approval from the plan before it will cover the drug. Without that okay, the plan may not pay.

Step Therapy

With step therapy, the plan wants you to try a different, often cheaper, medicine first. Only if that one doesn't work will it cover the drug you were prescribed.

Quantity Limits

Some plans cap how much of a drug they'll cover in a set time. For example, they might cover only 30 pills per month.

None of these rules means a drug is off-limits. But they can slow you down or change what you pay. Check them for every single medication on your list.

Don't Forget the Pharmacy Network

Where you fill your prescription can change your cost. Some plans have preferred pharmacies with lower copays. Others charge more at non-preferred pharmacies. Mail-order options can also be priced differently, and sometimes they save money on drugs you take every month.

Before you pick a plan, confirm that your usual pharmacy is in the network. Then check whether it's a preferred one. A quick call to the plan or the pharmacy can answer this in minutes.

Who Needs to Be Extra Careful Comparing Tiers?

Everyone benefits from a close look at drug coverage. But a few groups should be especially careful.

• Self-employed people and freelancers: With no employer plan to lean on, every dollar of out-of-pocket cost is yours. See our guide to health insurance for the self-employed.
• Families: More people means more prescriptions. Add up every family member's medicines before you compare.
• Small business owners: If you're picking a group plan, a formulary that works for one employee may not work for another. Read How to Choose Small Business Health Insurance in 2026.
• People between jobs: If you're weighing COBRA, comparing drug tiers can show whether another plan covers your medicines better. Check out COBRA Alternative Options After Job Loss in 2026.

Private Plans vs. Marketplace Plans for Prescriptions

Here's where an honest conversation matters. Private health plans are medically underwritten. That means they ask health questions before approving you. For people in good health who don't get a tax credit, they can be a strong fit.

Marketplace plans accept everyone. If you take costly medications or have a major health condition, a Marketplace plan is often the better choice. Health insurance isn't one size fits all. I always compare both side by side, and if a private plan isn't right for you, I'll tell you so.

Your medications play a big part in that decision. If you're curious how the two options stack up, read Private Plan vs. Marketplace Plan: Which Covers Emergencies Better?

Can You Ask for a Better Tier or Drug Coverage?

Sometimes, yes. Medicare Part D has a formal exception process. A person can ask for a tiering exception to get lower cost sharing on a covered drug placed in a higher tier. They can also request a formulary exception for a drug that isn't covered, or to waive certain rules. Your prescriber generally has to send a medical-necessity statement, and approval isn't automatic.

Quick note: I don't help with Medicare, since I work with people under 65. I mention it because it shows how formularies work and because many commercial plans have their own exception or appeal process too. Ask your insurer how to request one. Your doctor's office can often help.

A Quick Look at Part D's 2026 Cost Cap

You may have seen news about drug cost limits. For 2026, the Medicare Part D annual out-of-pocket threshold is $2,100, according to CMS. This is a Part D rule only. It doesn't apply to private or Marketplace plans for people under 65.

So don't assume your plan has the same cap. Always check your own plan's out-of-pocket maximum and how drug costs count toward it.

Formularies Can Change, So Double-Check

One last tip. Plans can update their formularies, and coverage rules can shift. That means the drug list you see today may not look the same later. Before you enroll, confirm details directly with the insurer. Then check again each year during enrollment.

If open enrollment is coming up, my post on 11 Health Insurance Annual Enrollment Tips for 2026 can help you plan ahead.

How I Can Help You Compare

Doing all this alone can feel like a part-time job. That's where I come in. I compare private plans and Marketplace plans side by side, and I look closely at your medications and the doctors you want to keep. My wife, Kela, works with me so our clients get quick answers.

We walk through each plan on a screen share so you know exactly what you're buying. My service costs you nothing. The insurance company pays me, and your price is the same whether you enroll with me or on your own. Quotes are estimates until the insurance company sets the final rate, and private plan approval depends on your health questions.

You can learn more about how it works, or read what a health insurance advisor does. You can also visit us on Google — Sterling Coverage Solutions to see what clients say.

Final Thoughts

Comparing prescription formulary tiers isn't about memorizing tier numbers. It's about finding what your exact medicines will cost, and what rules come with them, plan by plan. Start with your medication list, check each formulary, look at the copay or coinsurance, and add up the full-year cost.

You don't have to figure it out alone. Get an instant quote to start with 4 quick questions, or book a call and we'll go over your medications together. You can also call Sterling directly. I'd be happy to help you find coverage that fits.

FAQs

Q: How can I find out which tier my medication is on?

A: Look up your exact drug, strength, and form on each plan's current formulary, which is usually posted on the insurer's website. If you can't find it, call the plan's member line and ask. Tiers can differ from plan to plan, so check every plan you're considering.

Q: How do I compare the total yearly cost of my prescriptions across plans?

A: List each drug with its monthly amount, then find the tier cost, deductible rules, and any pharmacy differences on each plan. Multiply your monthly drug costs by 12 and add the yearly premium. Comparing totals gives you a much clearer picture than comparing premiums alone.

Q: What do prior authorization, step therapy, and quantity limits mean?

A: Prior authorization means the plan must approve a drug before covering it. Step therapy means you try another medicine first. Quantity limits cap how much of a drug the plan will cover in a set time. A drug can be on the formulary and still have these rules.

Q: Can a health plan change its drug formulary during the year?

A: Formularies and coverage rules can change, so it's smart to confirm details with the insurer before you enroll. Check again each year during enrollment too. If a change affects one of your medicines, ask the plan about your options.

Q: Can I ask my health plan to cover a drug at a lower tier or add it to the formulary?

A: Many plans have an exception or appeal process, and your prescriber generally has to explain why the drug is medically necessary. Approval isn't guaranteed. Ask your insurer how to start the request, and let your doctor's office help with the paperwork.