Drug Classes
Medicare Part D spending organized by therapeutic category. 190 drugs across 24 classes, totaling $63.49B in 2023.
Data: CMS Medicare Part D, 2023 (most current available) · Updated March 2026
Blood Thinners (Anticoagulants)
5 drugs · Top: Eliquis
$10.31B
14,064,739 claims
GLP-1 Receptor Agonists
6 drugs · Top: Ozempic
$8.51B
6,297,872 claims
Cancer/Oncology
13 drugs · Top: Revlimid
$6.71B
1,193,629 claims
Biologics & Immunotherapy
10 drugs · Top: Humira(Cf) Pen
$5.75B
738,787 claims
Inhalers & Respiratory
18 drugs · Top: Trelegy Ellipta
$5.73B
27,538,514 claims
SGLT2 Inhibitors
5 drugs · Top: Jardiance
$5.45B
5,223,231 claims
Insulins
14 drugs · Top: Lantus Solostar
$4.94B
6,882,935 claims
HIV/Antivirals
15 drugs · Top: Biktarvy
$3.10B
1,687,070 claims
Diabetes (Other)
10 drugs · Top: Januvia
$2.67B
22,787,802 claims
Antipsychotics
14 drugs · Top: Invega Sustenna
$2.43B
10,068,042 claims
ARBs (Angiotensin Blockers)
9 drugs · Top: Entresto
$1.74B
22,273,334 claims
Opioid Pain Medications
11 drugs · Top: Oxycodone Hcl
$1.05B
23,323,774 claims
Statins (Cholesterol)
6 drugs · Top: Atorvastatin Calcium
$915.1M
53,481,103 claims
Seizure/Epilepsy Medications
9 drugs · Top: Gabapentin
$911.5M
25,349,101 claims
Proton Pump Inhibitors
6 drugs · Top: Omeprazole
$586.4M
23,785,760 claims
Beta Blockers
6 drugs · Top: Metoprolol Succinate
$496.8M
30,405,641 claims
NSAIDs (Anti-inflammatory)
8 drugs · Top: Diclofenac Sodium
$443.0M
14,264,788 claims
Thyroid Medications
1 drug · Top: Levothyroxine Sodium
$435.3M
20,209,418 claims
Calcium Channel Blockers
4 drugs · Top: Amlodipine Besylate
$321.6M
24,261,667 claims
SNRIs (Antidepressants)
3 drugs · Top: Duloxetine Hcl
$253.7M
7,551,980 claims
SSRIs (Antidepressants)
5 drugs · Top: Sertraline Hcl
$236.4M
18,343,598 claims
Diuretics
6 drugs · Top: Furosemide
$220.5M
23,467,602 claims
ACE Inhibitors
3 drugs · Top: Lisinopril
$190.1M
18,722,530 claims
Benzodiazepines
3 drugs · Top: Alprazolam
$101.8M
11,823,167 claims
About Drug Classification
Drugs are grouped by their therapeutic mechanism — how they work in the body. This classification helps identify which categories drive the most Medicare spending and where cost-saving opportunities exist.
Blood thinners and GLP-1 receptor agonists together account for nearly $19 billion — more than the next four categories combined. The rapid growth of GLP-1 drugs (Ozempic, Mounjaro) for diabetes and weight loss is reshaping Medicare drug spending.
See our Most Prescribed Drugs analysis or Generic Adoption Gap for more context.