Medicare Part D — Prescription Drug Coverage Explained

If you are enrolled in Medicare and need help covering the cost of your prescription medications, Medicare Part D is the prescription drug coverage program designed for you. As an independent Medicare insurance broker serving clients across New York, New Jersey, and nationwide, I help seniors compare and enroll in Part D plans every day at no cost to you. Here is everything you need to know.

What Is Medicare Part D?

Medicare Part D is the prescription drug coverage component of Medicare. It is offered through private insurance companies approved by Medicare and helps cover the cost of prescription medications — reducing your out-of-pocket drug expenses significantly.

Part D coverage is available in two ways:

Standalone Part D plans (PDPs) — add prescription drug coverage to Original Medicare, combined with a Medicare Supplement plan
Medicare Advantage plans with drug coverage (MA-PDs) — most Medicare Advantage plans include Part D drug coverage built in

Who Needs Medicare Part D?

If you are enrolled in Original Medicare with a Medigap plan, you will need a standalone Part D plan to cover your prescriptions. Medigap plans do not include prescription drug coverage.

If you are enrolled in a Medicare Advantage plan that already includes drug coverage, you are already covered for Part D you do not need a separate plan.

Medicare Part D Costs in 2026

Part D plan costs vary by carrier, plan, and your location. Here is what to expect in 2026:

Monthly premium: Varies by plan — typically starting around $10–$15/month in most states, though premiums vary widely
Annual deductible: The maximum Part D deductible in 2026 is $615, though many plans have lower or no deductible
Copays and coinsurance: Vary by drug tier and plan — lower-tier drugs typically have lower copays
Out-of-pocket cap: In 2026, there is a $2,100 annual out-of-pocket cap on Part D drug costs, a significant improvement for seniors with high drug costs

Part D IRMAA Surcharge

Higher-income beneficiaries pay an additional surcharge on top of their Part D plan premium, known as the IRMAA surcharge. In 2026, the surcharge begins for individuals earning over $106,000 and couples earning over $212,000. This is separate from and in addition to the Part B IRMAA surcharge.

Understanding Part D Drug Formularies

Each Medicare Part D plan has its own list of covered drugs called a formulary. Drugs on the formulary are organized into tiers, and the tier your drug is on determines how much you pay:

Tier 1 — Generic drugs — lowest copay
Tier 2 — Preferred brand-name drugs — moderate copay
Tier 3 — Non-preferred brand-name drugs — higher copay
Tier 4 — Specialty drugs — highest copay or coinsurance

Before enrolling in any Part D plan, it is critical to verify that your specific medications are covered on the plan’s formulary and at what tier. A plan with a low monthly premium may cost you significantly more if your drugs are on a high tier. As an independent broker, I always run a drug-by-drug comparison for my clients before making a recommendation.

The Part D Late Enrollment Penalty

One of the most important things to understand about Part D is the late enrollment penalty. If you do not enroll in a Part D plan when you first become eligible, and you do not have other creditable drug coverage, you will face a permanent penalty added to your monthly premium for as long as you have Part D.

The penalty is calculated as 1% of the national base beneficiary premium for each month you were eligible but did not enroll. This penalty is permanent; it follows you for life.

Use our Part D Penalty Calculator to estimate what your penalty might be.

The $2,100 Out-of-Pocket Cap — A Major 2026 Change

One of the most significant improvements to Medicare Part D in recent years takes full effect in 2026: a $2,100 annual cap on out-of-pocket prescription drug costs. This means that once you have spent $2,000 on covered Part D drugs in a calendar year, your plan pays 100% of covered drug costs for the rest of the year.

This cap is a major benefit for seniors who take expensive specialty medications or have high annual drug costs, and it makes Part D significantly more valuable than in previous years.

When Can You Enroll in Medicare Part D?

Initial Enrollment Period (IEP): When you first become eligible for Medicare, a 7-month window around your 65th birthday
Annual Enrollment Period (AEP): October 15 – December 7 each year, switch Part D plans for coverage beginning January 1
Special Enrollment Period (SEP): Triggered by qualifying life events such as losing creditable drug coverage

How to Choose the Right Part D Plan

Choosing the right Part D plan requires comparing several factors:

Your specific medications — verify all your drugs are on the formulary
Drug tiers — check what tier each of your medications falls into
Pharmacy network — confirm your preferred pharmacy is in-network
Monthly premium — balance premium cost against drug costs
Annual deductible — some plans have a $0 deductible for preferred drugs
Total estimated annual cost — the most important number to compare

As an independent broker, I run this comparison for you across all available Part D plans in your area completely free of charge. The plan with the lowest premium is not always the lowest total cost, and I make sure you understand the full picture before enrolling.

Frequently Asked Questions — Medicare Part D

Do I need Part D if I have a Medicare Advantage plan?

Most Medicare Advantage plans already include Part D drug coverage; you do not need a separate Part D plan. However, if your Medicare Advantage plan does not include drug coverage, you may be able to enroll in a standalone Part D plan.

What happens if I miss my Part D enrollment window?

If you do not enroll when first eligible and do not have creditable drug coverage, you will face a permanent late enrollment penalty. Use our Part D Penalty Calculator to estimate your penalty.

Can I change my Part D plan every year?

Yes — during the Annual Enrollment Period (October 15 – December 7), you can switch Part D plans for coverage beginning January 1. I recommend reviewing your Part D plan every year during AEP since formularies, premiums, and drug tiers can change annually.

What is creditable prescription drug coverage?

Creditable coverage is drug coverage that is at least as good as Medicare Part D, such as coverage from an employer plan or union. If you have creditable coverage, you can delay Part D enrollment without penalty. When that coverage ends, you have a Special Enrollment Period to enroll in Part D.

Get Your Free Medicare Part D Consultation

As an independent Medicare broker, I compare Part D plans across all available carriers in your area, running a drug-by-drug analysis to make sure you get the coverage that works best for your specific medications at the lowest total cost. My services are completely free of charge.

I serve clients across New York, New Jersey, and nationwide — by phone, video, or in person.

📞 Contact Craig Smith Insurance Group today at (917) 740-1895 for your free Part D consultation. No pressure, no obligation, just straightforward guidance from an independent broker who genuinely cares about getting you the right coverage.