Compare PDP Plans
What to look for when shopping Prescription Drug Plans.
Why Comparing Drug Plans Matters
Not all Medicare Part D plans are the same. The plan that covers your neighbor's medications might not work well for yours.
Each plan has its own list of covered drugs (called a formulary) and different costs. The wrong choice could cost you hundreds or thousands per year.
What to Look for When Comparing Plans
1. Are Your Medications Covered?
This is the most important factor. A plan is useless if it doesn't cover your drugs.
Check each plan's formulary for all your medications. Don't assume similar drugs are covered the same way.
2. What Tier Are Your Drugs On?
Plans organize drugs into different cost levels called tiers. Lower tiers cost less.
- Tier 1: Generic drugs (lowest cost)
- Tier 2: Preferred brand drugs
- Tier 3: Non-preferred brand drugs
- Tier 4: Specialty drugs (highest cost)
3. What Are the Copays?
Even if your drug is covered, you'll pay different amounts depending on the plan.
Some plans charge a flat copay (like $10). Others charge coinsurance (like 25% of the drug cost).
| Drug Tier | Plan A Cost | Plan B Cost | Plan C Cost |
|---|---|---|---|
| Tier 1 (Generic) | $5 copay | $10 copay | 15% coinsurance |
| Tier 2 (Preferred Brand) | $25 copay | $40 copay | 25% coinsurance |
| Tier 3 (Non-preferred) | $60 copay | 45% coinsurance | 50% coinsurance |
| Tier 4 (Specialty) | 25% coinsurance | 33% coinsurance | 25% coinsurance |
Don't Forget About the Deductible
Many Part D plans have a yearly deductible. You pay full price for drugs until you meet it.
In 2025, the maximum deductible is $590. Some plans have lower deductibles or no deductible at all.
Example: How Deductibles Affect Costs
Let's say you take a brand-name drug that costs $200 per month:
- Plan with $0 deductible: You pay your copay from day one
- Plan with $590 deductible: You pay $200/month for the first 3 months, then your copay starts
Check Your Pharmacy Network
Not all pharmacies work with every Part D plan. Using an out-of-network pharmacy costs more.
Make sure your preferred pharmacy is in the plan's network. Check both retail locations and mail-order options.
Consider Total Annual Costs
Don't just look at monthly premiums. Calculate your total yearly costs including:
- Monthly premium × 12
- Annual deductible
- Expected drug copays for the year
Real Example
Plan A: $20/month premium, $590 deductible, $30 copay for your drug
Plan B: $60/month premium, $0 deductible, $15 copay for your drug
If you take one drug monthly:
- Plan A total: $240 + $590 + $360 = $1,190
- Plan B total: $720 + $0 + $180 = $900
Plan B costs $40 more per month but saves $290 per year.
The $2,000 Out-of-Pocket Cap
Starting in 2025, there's a $2,000 annual limit on what you pay for Part D drugs. Once you hit this amount, your drugs are free for the rest of the year.
This cap makes expensive specialty medications more affordable. But you still want to minimize costs before reaching the cap.
Special Rules and Restrictions
Prior Authorization
Some drugs require approval from the plan before they'll cover them. This can delay getting your medication.
Quantity Limits
Plans might limit how much of a drug you can get at once. A 90-day supply might be cheaper than three 30-day fills.
Step Therapy
Some plans require you to try cheaper drugs first before covering more expensive options.
Using a Plan Comparison Tool
Use a reputable plan comparison tool to input your medications and pharmacy preferences so you can see estimated annual costs.
Organize results by total yearly cost, not just premium. Re-run a comparison if your drug list changes mid-year.
Pro tip: Update your drug list in Plan Finder if your medications change during the year. What looked like the best plan might not be anymore.
When to Switch Plans
Review your Part D plan every year during Open Enrollment (October 15 to December 7).
Switch if:
- Your drugs are no longer covered
- Your drugs moved to higher tiers
- You found a plan with significantly lower total costs
- Your pharmacy is no longer in the network
What If You Don't Take Any Medications?
You should still get a Part D plan to avoid late enrollment penalties.
Look for the cheapest plan available in your area. You can always switch to better coverage if you start taking medications later.
Getting Help With Plan Comparison
Comparing Part D plans takes a little structure. Make a one-page list of your drugs (name, dosage, frequency) plus your preferred pharmacies.
Work through an internal checklist: Are all drugs covered? Any tier changes? Which plan has lowest projected annual total (premium + deductible + copays)?
If you want a guided walkthrough, schedule a review and bring your medication list. Solid preparation saves time and prevents surprises later.