Formulary Coverage Intelligence
Tier placement, prior authorization rates, and utilization controls across 329 Medicare Part D plans for 1,457 drugs. Identify access barriers before they impact your members.
Coverage by Drug Class
Average Tier 1 placement rate across Part D plans by therapeutic class. Higher rates mean broader generic access.
Highest Formulary Inclusion
Drugs appearing on the most Part D plan formularies at Tier 1 (preferred generic). Ranked by raw plan count across 329 plans surveyed.
| Drug | Class | Tier 1 Plans | Coverage | PA Rate |
|---|---|---|---|---|
| Levothyroxine | Thyroid Hormone | 6,645 / 329 | 100% | 4.6% |
| Warfarin | Vitamin K Antagonist (Anticoagulant) | 5,705 / 329 | 100% | None |
| Metoprolol | Beta-Adrenergic Blocker | 2,417 / 329 | 100% | None |
| Diltiazem | Calcium Channel Blocker | 2,406 / 329 | 100% | None |
| Amoxicillin | Aminopenicillin (Antibiotic) | 2,248 / 329 | 100% | None |
| Lamotrigine | Anti-epileptic Agent | 2,170 / 329 | 100% | 31.6% |
| Prednisone | Corticosteroid | 2,138 / 329 | 100% | 319.8% |
| Estradiol | Estrogen | 2,083 / 329 | 100% | 52.0% |
| Potassium Chloride | Potassium Supplement | 1,964 / 329 | 100% | 4.9% |
| Risperidone | Atypical Antipsychotic | 1,862 / 329 | 100% | 185.7% |
| Norethindrone and Ethinyl Estradiol | Estrogen | 1,777 / 329 | 100% | 12.2% |
| Verapamil | Calcium Channel Blocker | 1,582 / 329 | 100% | None |
| Ibuprofen | Nonsteroidal Anti-inflammatory Drug | 1,491 / 329 | 100% | None |
| Lisinopril | ACE Inhibitor | 1,476 / 329 | 100% | None |
| Amlodipine and Benazepril | Dihydropyridine Calcium Channel Blocker | 1,466 / 329 | 100% | None |
| Hydrocortisone | Corticosteroid | 1,425 / 329 | 100% | None |
| Levonorgestrel and Ethinyl Estradiol | Estrogen | 1,380 / 329 | 100% | None |
| Furosemide | Loop Diuretic | 1,364 / 329 | 100% | None |
| Hydrochlorothiazide | Thiazide Diuretic | 1,282 / 329 | 100% | 0.6% |
| Carvedilol | alpha-Adrenergic Blocker | 1,280 / 329 | 100% | None |
| Azithromycin | Macrolide (Antibiotic) | 1,267 / 329 | 100% | 10.0% |
| Glipizide | Sulfonylurea | 1,239 / 329 | 100% | None |
| Simvastatin | HMG-CoA Reductase Inhibitor | 1,217 / 329 | 100% | 1.5% |
| Triamcinolone Acetonide | Corticosteroid | 1,169 / 329 | 100% | None |
| Terazosin | alpha-Adrenergic Blocker | 1,164 / 329 | 100% | None |
| Clonidine | Central alpha-2 Adrenergic Agonist | 1,128 / 329 | 100% | 1.8% |
| Lithium Carbonate | 1,111 / 329 | 100% | None | |
| Naproxen | Nonsteroidal Anti-inflammatory Drug | 1,108 / 329 | 100% | None |
| Fluoxetine | Serotonin Reuptake Inhibitor | 1,103 / 329 | 100% | None |
| Haloperidol | Typical Antipsychotic | 1,052 / 329 | 100% | 165.3% |
Highest Prior Authorization Rates
Drugs most frequently requiring PA across Part D plans. High PA rates increase admin burden and delay patient access.
Step Therapy Requirements
Drugs requiring step therapy (try-and-fail) before coverage approval. Patients must first try a preferred alternative.
| Drug | Step Therapy Rate | Plans Requiring ST |
|---|---|---|
| Iloperidone | 100% | 984 / 329 |
| Methotrexate | 100% | 620 / 329 |
| Levomilnacipran | 100% | 575 / 329 |
| Perampanel | 100% | 501 / 329 |
| Lamotrigine | 100% | 437 / 329 |
| Risperidone | 100% | 414 / 329 |
| Aripiprazole | 100% | 372 / 329 |
| Clozapine | 100% | 345 / 329 |
| Gepirone | 100% | 328 / 329 |
| Asenapine | 97% | 320 / 329 |
| Duloxetine | 88% | 288 / 329 |
| Febuxostat | 80% | 263 / 329 |
| Esomeprazole | 78% | 258 / 329 |
| Cariprazine | 78% | 256 / 329 |
| Xanomeline and Trospium | 77% | 252 / 329 |
Formulary data reflects Medicare Part D plan coverage and may not apply to commercial plans. Tier placement and UM policies change quarterly. Some drugs appear on multiple tiers across different plans; counts reflect total NDC-level formulary entries. Source: CMS Part D Formulary Files.