Quick Answer
Medicare Part D plans offer mail order pharmacy options that typically provide a 90-day supply for the cost of a 60-day supply (or less). Mail order is best for maintenance medications you take regularly. In 2026, the Part D $2,000 out-of-pocket cap makes mail order even more valuable for managing costs.
Coverage Comparison by Plan Type
| Plan Type | Coverage | Notes |
|---|---|---|
| Mail Order (90-day) | Lower cost per dose | Best for maintenance meds; 2–3 copays for 90-day supply |
| Retail Pharmacy (30-day) | Standard cost-sharing | Best for short-term or new prescriptions |
| Preferred Retail (90-day) | Similar to mail order | Some plans offer preferred retail as alternative to mail order |
| Extra Help + Mail Order | Lowest cost | Extra Help copays apply; mail order maximizes savings |
Understanding Your Coverage Options
How Medicare Mail Order Pharmacies Work
Medicare Part D plans are required to offer access to a mail order pharmacy for maintenance medications. You submit your prescription (by mail, phone, or online), and the pharmacy ships a 90-day supply directly to your home. Most plans charge 2–2.5 copays for a 90-day supply, effectively giving you a free month's supply.
Mail order is ideal for medications you take every day for chronic conditions - like blood pressure, cholesterol, diabetes, or thyroid medications. It is not appropriate for antibiotics, controlled substances, or medications you need immediately.
What It Covers
- 90-day supply of maintenance medications (chronic conditions)
- Typically costs 2–2.5 copays for 90 days (vs. 3 copays at retail)
- Free home delivery - no trips to the pharmacy
- Automatic refill reminders and easy online management
What It Doesn't Cover
- Does not cover controlled substances (Schedule II drugs) in most cases
- Does not cover medications needed immediately - 7–10 day shipping delay
- Does not cover medications not on the plan's formulary
How Much Can You Save with Mail Order?
The savings from mail order depend on your plan's cost-sharing structure. A typical example: a generic maintenance drug with a $10 retail copay costs $30 for 90 days at retail (3 copays) but only $20 for 90 days by mail order (2 copays) - saving $10 every 90 days, or $40/year per drug.
With the 2026 Part D $2,000 OOP cap, mail order helps you reach the cap faster on expensive brand-name drugs, after which the plan pays 100%. For high-cost specialty drugs, this can mean significant savings.
What It Covers
- Savings of 25–50% per dose for many maintenance medications
- Counts toward Part D OOP cap - same as retail pharmacy purchases
- Extra Help copays apply at mail order pharmacies
- Insulin: $35/month cap applies at mail order pharmacies
What It Doesn't Cover
- Savings vary by plan and drug tier - not all drugs are cheaper by mail
- Brand-name drugs may not have significant mail order savings
- Does not reduce the Part D premium
How to Use Your Plan's Mail Order Pharmacy
Each Part D plan has a designated mail order pharmacy (e.g., CVS Caremark, Express Scripts, OptumRx). To use it: (1) Ask your doctor to write a 90-day prescription, (2) Submit it online, by phone, or by mail to the plan's mail order pharmacy, (3) Provide your payment information, (4) Receive your medication in 7–10 business days.
Most plans allow you to set up automatic refills so you never run out. You can also transfer existing retail prescriptions to mail order through the plan's website or by calling customer service.
What It Covers
- Online, phone, and mail submission options for prescriptions
- Automatic refill programs to prevent running out of medications
- Transfer of existing retail prescriptions to mail order
- Secure packaging and temperature-controlled shipping for sensitive medications
What It Doesn't Cover
- Does not guarantee same-day or next-day delivery
- Does not cover medications that require refrigeration in all cases - verify with plan
- Does not cover prescriptions written for less than a 90-day supply at mail order rates
Extra Help and Mail Order Prescriptions
If you qualify for Extra Help (Low Income Subsidy), your Part D copays are dramatically reduced - typically $4.90 for generics and $12.15 for brand-name drugs in 2026. These reduced copays apply at mail order pharmacies as well as retail pharmacies.
For Extra Help recipients, mail order can further reduce costs by providing a 90-day supply at 2–2.5 times the reduced copay, rather than 3 times. This maximizes the value of the Extra Help benefit.
What It Covers
- Extra Help copays ($4.90 generic / $12.15 brand in 2026) apply at mail order
- 90-day supply at mail order = 2–2.5 Extra Help copays
- No coverage gap or catastrophic phase for Extra Help recipients
- Automatic Extra Help enrollment for Medicaid/SSI recipients
What It Doesn't Cover
- Extra Help does not cover drugs not on the plan's formulary
- Extra Help does not cover OTC medications
- Extra Help copays may differ slightly by plan - verify with your specific plan
Mail Order vs. Retail Pharmacy Cost Comparison (2026)
| Drug Type | Retail 30-Day | Mail Order 90-Day | Extra Help Mail Order | Notes |
|---|---|---|---|---|
| Generic (maintenance) | $10/month ($120/year) | $20/90 days ($80/year) | $4.90 × 2 = $9.80/90 days | Best savings with mail order |
| Preferred brand | $45/month ($540/year) | $90/90 days ($360/year) | $12.15 × 2 = $24.30/90 days | Significant mail order savings |
| Non-preferred brand | $95/month ($1,140/year) | $190/90 days ($760/year) | $12.15 × 2 = $24.30/90 days | Check formulary for alternatives |
| Insulin | $35/month cap | $35/month cap applies | $4.90 copay | $35/month insulin cap applies at mail order |
| Specialty drug | 33% coinsurance (up to OOP cap) | 33% coinsurance (up to OOP cap) | $12.15 copay | OOP cap: $2,000 in 2026 |
✦ Important Exceptions
Controlled Substances
Most Schedule II controlled substances (e.g., opioids, stimulants) cannot be filled by mail order due to federal law.
New Prescriptions
Many plans require a first fill at a retail pharmacy before allowing mail order for a new medication.
Specialty Medications
Some specialty drugs require a specialty pharmacy rather than standard mail order. Check your plan's formulary.
Preferred Retail as Alternative
Some plans offer preferred retail pharmacies (e.g., Walmart, Costco) with 90-day supplies at mail order prices.
✦ Legislative Updates
Part D $2,000 OOP Cap (2025)
PassedThe Inflation Reduction Act capped Part D out-of-pocket costs at $2,000/year starting in 2025, making mail order more valuable for high-cost drugs.
$35 Insulin Cap Continues (2026)
PassedThe $35/month insulin cap applies at all Part D pharmacies, including mail order, in 2026.
10 Negotiated Drug Prices (2026)
PassedCMS negotiated prices for 10 high-cost drugs take effect in 2026, reducing costs at all pharmacies including mail order.
How to Get the Most from Mail Order
To maximize mail order savings, ask your doctor to write all maintenance prescriptions for a 90-day supply. Set up automatic refills through your plan's mail order portal and request refills at least 2 weeks before you run out.
Compare your plan's mail order copays against preferred retail pharmacies (like Walmart or Costco) - some plans offer equivalent 90-day pricing at preferred retail locations, which may be more convenient.
Mail Order Prescription Checklist
- Ask your doctor for a 90-day prescription for all maintenance medications
- Verify your medication is on your plan's formulary at the mail order tier
- Set up automatic refills to avoid running out of medications
- Compare mail order vs. preferred retail pharmacy costs for your specific drugs
- If you have Extra Help, confirm your reduced copays apply at the mail order pharmacy
- Keep a list of your medications and refill dates to manage the 7–10 day shipping window
- For specialty drugs, check if your plan requires a specialty pharmacy instead of mail order
✦ Frequently Asked Questions
David Haass
AuthorDavid Haass is a licensed Medicare expert who has been helping beneficiaries navigate their Medicare options for over a decade.
Ashlee Zareczny
ReviewerAshlee Zareczny is a licensed Medicare agent dedicated to helping those eligible for Medicare find the best coverage options.