Medicare Part D drugs starting with I
76 drugs start with I; 41 of them are on at least 90% of 2026 Part D formularies. Part D spending was highest for Imbruvica in 2024: $2.3 billion, what plans and patients paid at the pharmacy before rebates.
Which drugs start with I?
| Drug | Plans covering | Usual tier | Medicare spending, 2024 |
|---|---|---|---|
| Ibandronic acid | 97.3% | Tier 2 | $25 million |
| Ibrance (palbociclib) | 100% | Tier 5 | $2.0 billion |
| Ibtrozi (taletrectinib) | 100% | Tier 5 | no 2024 match |
| Ibu (ibuprofen) | 99.7% | Tier 1 | $2 million |
| Ibuprofen | 100% | Tier 1 | $52 million |
| Icatibant | 100% | Tier 5 | $32 million |
| Iclevia (ethinyl estradiol / levonorgestrel) | 89.9% | Tier 2 | no 2024 match |
| Iclusig (ponatinib) | 100% | Tier 5 | $160 million |
| Icosapent ethyl | 31.9% | Tier 4 | $143 million |
| Idhifa (enasidenib) | 100% | Tier 5 | $185 million |
| Ilevro (nepafenac) | 49.1% | Tier 3 | $15 million |
| Ilumya (tildrakizumab-asmn) | 0.6% | Tier 5 | $34 million |
| Imatinib | 100% | Tier 4 | $157 million |
| Imbruvica (ibrutinib) | 100% | Tier 5 | $2.3 billion |
| Imipramine hydrochloride | 100% | Tier 2 | $5 million |
| Imipramine pamoate | 7.8% | Tier 2 | $2 million |
| Imiquimod | 100% | Tier 2 | $7 million |
| Imitrex (sumatriptan) | under 0.1% | Tier 1 | $5 million |
| Imkeldi (imatinib) | 100% | Tier 5 | no 2024 match |
| Imovax (rabies vaccine) | 100% | Tier 1 | no 2024 match |
| Impavido (miltefosine) | 100% | Tier 5 | $1 million |
| Imuran (azathioprine) | 1.6% | Tier 4 | $461 thousand |
| Imvexxy (estradiol) | 9% | Tier 3 | $14 million |
| Inbrija (levodopa) | 65.8% | Tier 5 | $28 million |
| Incassia (norethindrone) | 96.3% | Tier 2 | $89 thousand |
| Increlex (mecasermin) | 100% | Tier 5 | no 2024 match |
| Incruse (umeclidinium) | 65.7% | Tier 3 | $376 million |
| Indapamide | 99.8% | Tier 1 | $5 million |
| Inderal (propranolol hydrochloride) | under 0.1% | Tier 1 | $8 million |
| Indocin (indomethacin) | 2.3% | Tier 5 | $527 thousand |
| Indomethacin | 57.5% | Tier 2 | $4 million |
| Infanrix (DTaP vaccine) | 100% | Tier 1 | $18 thousand |
| Ingrezza (valbenazine) | 48.3% | Tier 5 | $2.0 billion |
| Inluriyo (imlunestrant) | 100% | Tier 5 | no 2024 match |
| Inlyta (axitinib) | 100% | Tier 5 | $439 million |
| InnoPran (propranolol hydrochloride) | under 0.1% | Tier 1 | $3 million |
| Inpefa (sotagliflozin) | 1.5% | Tier 3 | $6 million |
| Inqovi (cedazuridine / decitabine) | 100% | Tier 5 | $95 million |
| Inrebic (fedratinib) | 100% | Tier 5 | $45 million |
| Inspra (eplerenone) | under 0.1% | Tier 1 | $349 thousand |
Show the other 36 drugs
| Drug | Plans covering | Usual tier | Medicare spending, 2024 |
|---|---|---|---|
| Insulin glargine | 9.6% | Tier 3 | $3 million |
| Insulin glargine-yfgn | 14.9% | Tier 3 | $36 million |
| Insulin lispro | 52.2% | Tier 3 | $17 million |
| Insulin lispro / insulin lispro protamine, human | 28.3% | Tier 3 | no 2024 match |
| Intelence (etravirine) | 100% | Tier 4 | $2 million |
| Intralipid (soybean oil) | 74.3% | Tier 4 | $229 thousand |
| Intrarosa (prasterone) | 0.8% | Tier 4 | $4 million |
| Introvale (ethinyl estradiol / levonorgestrel) | 92.5% | Tier 2 | no 2024 match |
| Invega (paliperidone palmitate) | 100% | Tier 4 | $2 million |
| Inveltys (loteprednol etabonate) | 11.8% | Tier 3 | $2 million |
| Invokamet (canagliflozin / metformin hydrochloride) | 13.8% | Tier 4 | $27 million |
| Invokana (canagliflozin) | 13.8% | Tier 4 | $272 million |
| Inzirqo (hydrochlorothiazide) | 0.1% | Tier 4 | no 2024 match |
| Iopidine (apraclonidine) | 2.1% | Tier 4 | $37 thousand |
| Ipol (polio vaccine) | 100% | Tier 1 | $764 thousand |
| Ipratropium bromide | 100% | Tier 2 | $64 million |
| Iqirvo (elafibranor) | 7.7% | Tier 5 | $10 million |
| Irbesartan | 100% | Tier 1 | $55 million |
| Iressa (gefitinib) | 0.4% | Tier 1 | $1 million |
| Isentress (raltegravir) | 100% | Tier 3 | $113 million |
| Isibloom (desogestrel / ethinyl estradiol) | 94.5% | Tier 2 | $117 thousand |
| Isolyte P (dibasic potassium phosphate and 4 more ingredients) | 69.4% | Tier 4 | no 2024 match |
| Isolyte S (magnesium chloride and 6 more ingredients) | 67.2% | Tier 4 | no 2024 match |
| Isoniazid | 100% | Tier 1 | $352 thousand |
| Isosorbide dinitrate | 100% | Tier 2 | $28 million |
| Isosorbide mononitrate | 100% | Tier 1 | $63 million |
| Isotretinoin | 96.3% | Tier 4 | $2 million |
| Isradipine | 44.8% | Tier 4 | $1 million |
| Istalol (timolol) | under 0.1% | Tier 1 | $652 thousand |
| Isturisa (osilodrostat) | 3.9% | Tier 5 | $66 million |
| Itovebi (inavolisib) | 100% | Tier 5 | $1 million |
| Itraconazole | 100% | Tier 4 | $7 million |
| Ivabradine | 100% | Tier 4 | $5 million |
| Ivermectin | 100% | Tier 3 | $12 million |
| Iwilfin (eflornithine) | 100% | Tier 5 | no 2024 match |
| Ixiaro (Japanese encephalitis vaccine) | 100% | Tier 1 | $1 million |
Source: CMS Part D formulary file, 2026 second quarter; CMS Medicare Part D Spending by Drug, 2024.
What else should you check?
- Every drug, by letterAnd the 20 that cost Medicare most
- Stand-alone drug plans for 2027Premiums and deductibles
- Part D in 2027What changes for drug plans