Medicare Part D: What It Covers, Who It Helps, and How to Save on Prescription Drugs

When you’re on Medicare, Medicare Part D, the prescription drug coverage component of Medicare that helps pay for medications. It’s not automatic—you have to enroll in a plan, either through a private insurer or a Medicare Advantage plan that includes drug coverage. Without it, you could pay full price for things like insulin, blood pressure pills, or cholesterol meds—costs that can hit $500 a month or more. And while Part D doesn’t cover everything, it’s the main way seniors and people with disabilities in the U.S. get affordable access to their meds.

Part D plans vary a lot. Some have low monthly premiums but high out-of-pocket costs after you hit the deductible. Others charge more each month but cover more of your drugs right away. What matters most is your list of medications. If you take generic drugs, lower-cost versions of brand-name medications that work the same way like levothyroxine or metformin, you’ll usually save big. But if you’re on a high-cost drug like a specialty cancer med, you might hit the coverage gap—also called the donut hole. That’s where copay assistance, programs that help reduce what you pay at the pharmacy, often through patient foundations or manufacturer discounts can make a huge difference. In 2025, thanks to the Inflation Reduction Act, you won’t pay more than $35 a month for insulin, and out-of-pocket costs for other drugs will be capped at $2,000 a year. That’s a game-changer.

But here’s the catch: not all plans cover the same drugs. Each one has a formulary—a list of approved medications. If your doctor prescribes something not on your plan’s list, you might get stuck paying full price unless you file an exception. That’s why checking your plan’s formulary every year during open enrollment is critical. Also, many people don’t realize they qualify for Medicare Extra Help, a federal program that cuts Part D costs for people with limited income. If your income is under $21,500 (or $29,100 for a couple), you could pay almost nothing for your meds. You don’t have to apply for it every year—once approved, it rolls over.

And then there’s the hidden stuff: drug interactions. If you’re taking ashwagandha for stress or CoQ10 for heart health, you might not realize they can interfere with your thyroid meds or blood pressure pills. That’s why your Part D plan doesn’t just track what you buy—it can flag dangerous combos. But you still need to tell your pharmacist and doctor about every supplement you take. A lot of the posts below cover these exact risks—how generic drugs work, why some people react badly to them, how to get financial help, and what to watch out for when mixing meds and supplements.

What you’ll find here isn’t theory. These are real stories from people who’ve been there: someone who saved $1,200 a year switching to generic Claritin, another who avoided hospitalization by spotting a dangerous interaction between ashwagandha and levothyroxine, and folks who used patient advocacy groups to get free or low-cost meds when insurance fell short. Whether you’re new to Medicare Part D or you’ve been on it for years, this collection gives you the tools to stop overpaying, avoid dangerous mistakes, and actually understand what your plan does—and doesn’t—cover.