Pick Your Part D Plan Without Overpaying

Most people spend more time picking a Netflix subscription than they do choosing their Medicare Part D drug plan. I’ve watched that mistake cost people hundreds of dollars a year, sometimes over a thousand, and it’s entirely avoidable.

Here’s the thing: Part D plans vary wildly, even within the same zip code. Two neighbors on identical medications can pay completely different amounts depending on which plan they chose, or whether they chose at all. If you’re enrolled in Original Medicare (Parts A and B) and haven’t picked a drug plan, you may already be racking up a late enrollment penalty that follows you permanently. That gets our attention fast.

So let’s get into it. No fluff, no alphabet-soup jargon without explanation.

What Part D Actually Covers (and What It Doesn’t)

Part D is Medicare’s prescription drug coverage. It’s offered through private insurance companies that are approved by Medicare, and it works alongside Original Medicare or as part of a Medicare Advantage plan (Part C) that already bundles drug coverage in.

Every Part D plan must cover at least two drugs in each major therapeutic category, but beyond that floor, plans have real latitude. They publish a document called a formulary, which is just their list of covered drugs. Your Metformin might be on Plan A’s formulary at Tier 1 (lowest cost) and on Plan B’s formulary at Tier 3 (significantly higher cost), or not covered at all. This is why picking the cheapest monthly premium is usually a mistake.

What Part D doesn’t cover: most over-the-counter medications, vitamins, and cosmetic drugs. Some plans add extra value here, but the standard Part D benefit doesn’t touch those.

The Real Cost of a Part D Plan Has Four Parts

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Most people look at the monthly premium and stop there. Don’t.

The true out-of-pocket cost of a Part D plan comes from four pieces working together: the premium (what you pay every month regardless of whether you fill a prescription), the deductible (what you pay before coverage kicks in, currently up to $590 for standard Part D plans in 2026), your copays or coinsurance on each prescription, and the pharmacy network (because getting your drug at an out-of-network pharmacy can blow up your costs fast).

There’s one more thing to understand this year: the $2,000 out-of-pocket cap. Starting in 2025, the Inflation Reduction Act capped what Medicare Part D enrollees pay out-of-pocket annually at $2,000. That’s a genuinely significant protection, especially for people on expensive specialty drugs. If you’re paying more than $2,000 in drug costs in a calendar year, something is wrong. Check your plan.

I’ve seen people fixate on a $12/month premium plan and end up paying $80 per refill because their drug sits at Tier 4. A plan with a $45 premium that covers the same drug at Tier 2 for a $15 copay is objectively the better deal. Do the math on your specific drugs, not on the sticker price.

How to Actually Compare Plans: The Medicare Plan Finder

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Medicare Part D Plan Finder (2026) · Medicare Specialist - Abt Insurance Agency on YouTube

Medicare.gov has a tool called the Plan Finder, and it’s genuinely one of the most useful things the government has ever built for consumers. I mean that. You can go to Medicare.gov/plan-compare and enter your specific prescriptions, doses, and preferred pharmacy, and it will calculate your estimated annual cost for every plan available in your area.

Here’s the step-by-step of how to use it effectively:

1. Gather your current medications first. Write down the exact drug name, dosage, and how often you take it. Don’t guess. Pull the bottles or call your pharmacy.
2. Go to Medicare.gov/plan-compare and either log in with your Medicare account or continue as a guest.
3. Enter your drugs one by one. The tool will auto-fill names as you type.
4. Add your preferred pharmacy. This matters more than most people realize. Many plans have “preferred pharmacies” (often large chains or mail-order) where your copays are lower. Costco, Walmart, and certain regional pharmacies sometimes qualify, and the savings can be $20-$40 per prescription compared to a non-preferred pharmacy.
5. Sort by “lowest drug and premium costs.” That column is the one that matters. It’s your real annual cost estimate, not just the premium.

Do this comparison every single year during Open Enrollment (October 15 through December 7). Plans change their formularies, their premiums, and their pharmacy networks annually, and your medication needs may have changed too. AARP’s Medicare resource center at aarp.org/health/medicare-insurance also has solid guidance on reading plan comparison results if the Medicare.gov interface feels overwhelming.

Tiers, Formularies, and the Exception Process

Every plan organizes its drugs into tiers, typically five. Tier 1 is generic drugs at the lowest cost. Tier 2 is preferred brand-name drugs. Tier 3 is non-preferred brands. Tier 4 and 5 are specialty drugs, sometimes costing hundreds of dollars per fill even with insurance.

Here’s what most people don’t realize: if your drug is on Tier 3 or 4, you can request what’s called a formulary exception. Your doctor submits a request to the plan explaining why a lower-tier alternative won’t work for you medically. Plans must respond within 72 hours (or 24 hours if it’s urgent). These get approved more often than people think. I’ve seen patients get Tier 4 drugs covered at Tier 2 costs this way.

Also worth knowing: some plans restrict certain drugs through prior authorization (PA), step therapy (trying a cheaper drug first), or quantity limits. If you’re on a medication that’s been working for you for years, check that the plan doesn’t require you to “step through” alternatives before covering what you already take. That’s a real disruption to your health, not just a paperwork issue.

Mail-Order Pharmacies: Worth It for Most People, Not for Everyone

Most Part D plans offer mail-order, often with 90-day supplies at reduced copays. If you’re on stable, long-term medications for things like blood pressure, diabetes, or thyroid conditions, mail-order is almost always cheaper. A drug that costs $30 for a 30-day supply at retail might cost $45 for 90 days by mail. That’s real savings.

That said, mail-order doesn’t work well for medications you take short-term, anything refrigerated that your area’s summer heat makes risky in transit, or when you’re still adjusting doses with your doctor. Use it strategically.

The Extra Help Program (Low Income Subsidy): Most People Who Qualify Don’t Know They Do

If your income is at or below roughly 150% of the federal poverty level, you may qualify for Extra Help, officially called the Low Income Subsidy (LIS). This is a federal program that dramatically reduces your Part D costs: lower or eliminated premiums, reduced deductibles, and very small copays (often $4 or less for generics, under $12 for brand drugs in 2026).

Millions of people qualify and haven’t applied. The Social Security Administration handles applications at ssa.gov/extrahelp, and it takes about 30 minutes. This is one of those cases where I’d say: if there’s any chance you qualify, just apply. The worst outcome is a denial letter.

The single most important thing you can do is run your own drugs through Medicare.gov’s Plan Finder every October. Plans shift. Your needs shift. Staying with the same plan out of habit is the most common and most expensive mistake I see. Fifteen minutes a year can easily save you $500 or more. That’s not a small thing on a fixed income.

This article is for informational purposes only. Medicare rules change annually. Always verify current plan details at Medicare.gov or by calling 1-800-MEDICARE (1-800-633-4227). This site does not sell insurance or recommend specific plans.

Sources

• Withings Body+ Smart Scale with BMI and Body Composition
• iHealth Track Wireless Blood Pressure Monitor
• Vive Folding Cane with Ergonomic Handle
• MART PRODUCTION
• Medicare For Dummies

Disclosure: As an Amazon Associate, we earn a small commission from qualifying purchases at no extra cost to you. We only recommend products that genuinely support the topics covered in this article.

• Medicare For Dummies (~$22), The definitive consumer guide to Medicare, enrollment windows, Part A/B/C/D, and supplement plans.
• Get What’s Yours for Medicare (~$17), Maximize your Medicare benefits and minimize out-of-pocket costs. Covers Part D drug coverage gaps and Medigap in depth.
• Get What’s Yours for Medicare (Original) (~$15), The original bestselling guide to navigating Medicare and Social Security timing, over 100,000 copies sold.

Recommended Resources

Disclosure: As an Amazon Associate, we earn a small commission from qualifying purchases at no extra cost to you. We only recommend products that genuinely support the topics covered in this article.

• Medicare For Dummies (~$22), The definitive consumer guide to Medicare, enrollment windows, Part A/B/C/D, and supplement plans.
• Get What’s Yours for Medicare (~$17), Maximize your Medicare benefits and minimize out-of-pocket costs. Covers Part D drug coverage gaps and Medigap in depth.
• Get What’s Yours for Medicare (Original) (~$15), The original bestselling guide to navigating Medicare and Social Security timing, over 100,000 copies sold.