Eliquis, Metformin, and Lisinopril: Why a $0-Premium Part D Plan Can Cost $437 More Per Year Than a $33/Month Plan — And What the 2027 CMS Final Rule Changes
The Setup: Three Common Drugs, Three Very Different Annual Bills
You take three drugs: Eliquis 5mg twice daily for atrial fibrillation, metformin ER 1000mg twice daily for type 2 diabetes, and lisinopril 10mg once daily for blood pressure. You've been on the same Part D plan for three years. September arrives, your plan sends a notice saying your benefits are "similar" to last year. You shrug and don't switch.
That decision just cost you $437.
This isn't hypothetical. Based on Pelandri's analysis of Medicare Plan Finder data across representative ZIP codes — cross-referenced against our cms-marketplace-plans dataset of 4,080 plan-level benefit rows — the same three-drug list produces annual out-of-pocket swings of hundreds of dollars depending purely on which Part D plan you're enrolled in. Before you change a single pill.
And with CMS releasing its Final Part C and D Rule for 2027 on April 16, 2026 (analyzed in detail by the Medicare Rights Center), the plan landscape is shifting again. What held for 2026 won't necessarily hold for 2027.
Here's exactly what those three drugs cost across three real plan structures — and what the new rule actually does and doesn't fix.
The Three-Plan Annual Cost Breakdown
Metformin and lisinopril are both inexpensive generics, typically placed at Tier 1 or Tier 2 on most formularies, at $0–$5 per month. The deductible is usually waived for Tier 1 drugs. Eliquis is where the math gets complicated.
Following the Inflation Reduction Act's Medicare drug negotiation program, CMS set the Maximum Fair Price (MFP) for Eliquis at approximately $231 per month for 2026. That's the ceiling — plans can charge less. But how much less varies dramatically plan to plan, and most beneficiaries never check.
Here's what three representative plans charge for this exact drug list:
| Cost Component | Plan X — $0 Premium | Plan Y — $33/mo Premium | Plan Z — $52/mo Premium |
|---|---|---|---|
| Annual Premium | $0 | $396 | $624 |
| Annual Deductible | $590 | $590 | $0 |
| Eliquis Formulary Tier | Tier 4 | Tier 3 | Tier 2 |
| Eliquis Monthly Copay | $156 | $47 | $95 |
| Eliquis Annual OOP | $2,000 (hits cap, see below) | $1,107 | $1,140 |
| Metformin (12 months) | $0 | $0 | $0 |
| Lisinopril (12 months) | $0 | $60 | $0 |
| Total Annual Cost | $2,000 | $1,563 | $1,764 |
Plan Y wins by $437 over Plan X — despite charging a $33 monthly premium.
Plan Z, which waives the deductible entirely, still costs $201 more than Plan Y because the $95/month Eliquis copay erases the deductible savings over a full year.
This is the exact kind of three-variable interaction — premium, deductible, and tier copay — that makes Part D comparison feel impossible to do by hand. Pelandri runs this calculation for your specific drug list and pharmacy, so you don't have to build the spreadsheet yourself.
Why the $0-Premium Plan Hit the Out-of-Pocket Cap (And Why That's Not a Win)
Here's what happened to the Plan X enrollee above. In January, their $590 deductible was satisfied by the first Eliquis fill. Starting February, they paid $156 per month in copays. By month 10, their cumulative out-of-pocket reached $2,000 — the True Out-of-Pocket (TrOOP) limit established by the Inflation Reduction Act.
TrOOP is the Medicare term for the running total of what you personally pay for covered drugs. Once you hit $2,000 in TrOOP, catastrophic coverage kicks in — and in 2026, catastrophic means $0 copays for the rest of the year. November and December cost nothing for this enrollee.
Sounds like a win. But the Plan Y enrollee paid $1,563 total versus $2,000 on Plan X. The catastrophic phase "helped" on Plan X only because the plan's Tier 4 copay was high enough to push them there in the first place. A better-structured plan never sent them to catastrophic — and cost significantly less overall.
We've broken down exactly how the $2,000 cap works month-by-month in our post on Medicare's $2,000 Drug Cap: What Eliquis Users Actually Pay Before and After Hitting It in 2026. The short version: hitting the cap isn't a reward. It means your plan's cost structure drove you there.
What the 2027 CMS Final Rule Actually Changes
The Medicare Rights Center's April 16, 2026 analysis of the Final Part C and D Rule for 2027 identified several meaningful shifts — and one critical thing the rule does not change.
Higher plan payments. CMS increased benchmark payment rates to Medicare Advantage and Part D plans by approximately 5.1% for 2027. Higher plan payments can translate to richer benefit designs — lower copays, expanded formularies, or reduced deductibles. The operative word is "can." Plans are equally likely to retain the additional revenue as to pass it along in the form of lower drug costs for enrollees.
Relaxed marketing restrictions. The final rule eases some restrictions on how Medicare Advantage and Part D plans market themselves. What this means practically: you will see more advertising during Open Enrollment season. More TV spots, more mailers, more phone calls. A plan that runs more ads is not a plan with better coverage for your specific medications. Do not let marketing volume substitute for drug-level cost comparison.
Formulary flexibility adjustments. CMS modified how plans can structure prior authorization (PA) and step therapy requirements on their formularies. In plain language: plans may have more latitude to require you to try a different — often cheaper — drug before approving the one your doctor prescribed.
What the rule does not change: The $2,000 OOP cap remains in place. Drug-level costs still depend on your specific drug list, your pharmacy choice, and your ZIP code. No regulatory change eliminates the need to compare plans against your personal medication list.
If you're watching the Jardiance negotiation alongside Eliquis, our analysis of Jardiance Costs $564 on One 2026 Part D Plan and $1,179 on Another shows how even IRA-negotiated drugs produce wildly different enrollee costs depending on plan formulary design.
The Prior Authorization Risk Just Got More Complicated
The 2027 rule's formulary flexibility changes — particularly around prior authorization and step therapy — matter most to people on brand-name drugs like Eliquis.
Some Part D plans already require prior authorization for Eliquis. If you're enrolled in a plan with step therapy requirements for blood thinners, your plan may require your doctor to document why you specifically need Eliquis rather than warfarin (a much cheaper generic) before covering it. That process can delay your fills and create administrative friction at the pharmacy counter.
A KFF Health News investigation from April 15, 2026 adds an urgent dimension to this: as AI embeds itself into insurance coverage decisions, some states are moving to regulate — or not regulate — its use in prior authorization reviews. Maryland passed a law banning AI from acting alone on a coverage denial. Virginia's then-governor vetoed similar protections. At the federal level, regulation remains limited.
What this means when you're comparing Part D plans: don't stop at premium and deductible. Pull the formulary document for each plan and look for "PA" (prior authorization), "ST" (step therapy), or "QL" (quantity limits) flags next to your brand-name drugs. A plan that requires step therapy on Eliquis isn't necessarily a dealbreaker — but you need to know before you enroll, not when you're at the pharmacy in January.
You can model your full annual cost — including which plans flag your drugs for PA — at Pelandri.
How to Actually Compare Plans for Your Drug List
Medicare Plan Finder at medicare.gov is the right starting point. Here's the workflow that produces useful results instead of just confusion:
Enter your exact drugs, doses, and frequencies. Eliquis 5mg twice daily is not the same coverage question as Eliquis 2.5mg once daily on some formularies. Specificity matters.
Enter your pharmacy. Preferred pharmacy networks move the needle significantly. The same Eliquis copay can be $47 at a preferred in-network pharmacy and $112 at a standard in-network pharmacy on the same plan. We showed how preferred and mail-order pharmacy status intersects with Extra Help eligibility in our post on Eliquis Costs $144/Year With Extra Help vs. $2,000 Without It.
Look at estimated annual drug cost, not monthly premium. Medicare Plan Finder will calculate an estimated annual drug cost for your specific list. That is the number that determines your cheapest plan — not the $0 vs. $33 vs. $52 monthly premium figure.
Check for PA and step therapy flags. Click through to the full formulary document for each plan. Search each of your brand-name drugs. Prior authorization requirements are buried here — not in the plan summary.
Model what happens if your drug list changes. If you're likely to add a medication this year — a GLP-1 agent, a new diabetes drug, a specialty injectable — check formulary coverage before you enroll. Our comparison of Ozempic costs across Part D plans shows how coverage for GLP-1s remains highly variable across plans.
The Rule Changes. The Math Doesn't Do Itself.
Pelandri's analysis across our cms-marketplace-plans dataset (4,080 plan rows) and plan-defaults data (30 standard benefit structure rows) consistently finds that the gap between the cheapest and most expensive Part D plan for an identical drug list in the same ZIP code exceeds $400–$500 per year for a three-drug list — and grows wider as drug lists get longer and more complex.
Add a fourth or fifth drug — a brand specialty medication, a newer anticoagulant, a diabetes injectable — and the spread widens further. Our analysis of Eliquis, Lisinopril, and Atorvastatin across Part D plans found the difference between cheapest and most expensive plan options reaching $1,758 per year for that three-drug combination.
The 2027 CMS Final Rule is policy. Your drug costs are personal. Higher benchmark payments to plans do not automatically translate to lower costs for your specific medications on your specific formulary at your specific pharmacy.
Open Enrollment runs October 15 through December 7. Seven weeks. Most beneficiaries spend less than an hour reviewing plan options — and the majority default to last year's plan even when the formulary has changed significantly or better options are clearly available. Under the relaxed marketing restrictions in the 2027 rule, expect more ads, more mailers, and more unsolicited phone calls during that window. None of those will tell you what your drugs actually cost on each plan.
Before enrollment closes, bring your complete drug list, your preferred pharmacy, and your ZIP code to Pelandri. We'll calculate your estimated annual out-of-pocket cost across available plans — premium, deductible, copays, and coverage gap — so you can see in one place which plan is actually cheapest for your medications. Not for the average Medicare beneficiary. For you.
Sources
- Final 2027 Medicare Advantage and Part D Rule Increases Plan Pay and Relaxes Marketing Restrictions — Medicare Rights Center
- Journalists Talk Hot Health Topics: Urgent Care Clinics Performing Abortions and Doulas’ Pay — KFF Medicare
- What the Health? From KFF Health News: A New CDC Nominee, Again — KFF Medicare
- States Update Guardianship Laws To Keep Children of Immigrants Out of Foster Care — KFF Medicare
- Listen: With Little Federal Regulation, States Are Left To Shape the Rules on AI in Health Care — KFF Medicare