Which Medical Specialties Drive the Most Drug Spending?

Not all prescribers are created equal when it comes to Medicare drug costs. A single oncologist may generate more drug spending in a month than a family physician does in a year. Understanding specialty-level variation is essential to making sense of the $275.6 billion Medicare Part D landscape.

The Specialty Spending Hierarchy

When we rank specialties by average total drug cost per provider, the results reveal a dramatic hierarchy. At the top sit oncologists and hematologists, whose per-provider drug costs regularly exceed $2 million annually. This reflects the extraordinary cost of cancer medications — immunotherapies, targeted therapies, and chemotherapy agents that can cost tens of thousands of dollars per treatment cycle.

Rheumatologists and gastroenterologists also rank high, driven by expensive biologic drugs for conditions like rheumatoid arthritis, Crohn's disease, and ulcerative colitis. A single prescription for adalimumab (Humira) or its biosimilars can cost Medicare thousands per month.

At the other end, specialties like optometry, podiatry, and clinical psychology generate relatively modest drug costs per provider — typically under $50,000 annually. Their prescribing scope is narrower, and the medications they prescribe tend to be lower-cost generics.

The Volume Leaders

While specialists top the per-provider cost charts, primary care dominates in absolute terms. Internal medicine, family practice, and nurse practitioners collectively account for the majority of total Medicare Part D spending — not because their individual costs are high, but because they represent the largest share of prescribers.

Family practice alone includes over 150,000 prescribers in the Medicare dataset. When you multiply even moderate per-provider costs across that many clinicians, the total dwarfs most specialty categories. This is why policy interventions targeting primary care prescribing patterns — even small percentage changes — can yield enormous aggregate savings.

Opioid Prescribing by Specialty

Specialty variation in opioid prescribing rates is one of the most striking patterns in the data. Pain management specialists have average opioid rates exceeding 35%, which is expected given their clinical focus. Anesthesiologists and physical medicine & rehabilitation providers also show elevated rates.

But what's more concerning are the specialties with unexpectedly high opioid rates. Some general practice and family medicine providers show opioid rates above 25%, well above the specialty average. Dentists, while prescribing fewer total medications, often have high opioid percentages due to post-procedure pain management being a dominant use case for their prescriptions.

Emergency medicine presents a unique pattern: relatively high opioid rates but typically for short-duration prescriptions. The concern shifts to whether those short prescriptions become the gateway to longer-term use managed by other providers.

Brand vs. Generic Preferences

The brand-name prescribing rate also varies significantly by specialty. Dermatologists tend to have some of the highest brand-name rates, driven by newer topical medications and biologics for conditions like psoriasis that lack generic equivalents.

Psychiatrists show higher-than-average brand rates for certain medication classes, particularly newer antipsychotics and antidepressants. The clinical reasoning is often that psychiatric medications are sensitive to formulation differences, though evidence for this is debated.

In contrast, infectious disease specialists and general internists tend toward generic prescribing, partly because many antibiotics and common chronic disease medications have been available as generics for years.

The Nurse Practitioner Factor

One of the most significant shifts in Medicare prescribing over the past decade has been the rise of nurse practitioners (NPs) and physician assistants (PAs). These providers now represent a growing share of all Medicare Part D prescribers, and their prescribing patterns don't always mirror those of physicians in the same specialty area.

On average, NPs and PAs generate lower per-provider drug costs than physicians, partly because they tend to manage less complex patients and prescribe fewer specialty medications. However, in some regions and practice settings, their opioid prescribing rates match or exceed physician averages, raising questions about supervision and training in controlled substance management.

What the Data Suggests

Specialty-level analysis reveals that blanket policies — like across-the-board prescribing limits or uniform prior authorization requirements — may be poorly calibrated. An oncologist prescribing $3 million in cancer drugs is fundamentally different from a family physician prescribing $200,000 in chronic disease medications. Risk models and cost benchmarks need specialty-specific calibration to be meaningful.

Our risk scoring methodology accounts for this by comparing providers against their specialty peers rather than the overall population. A high-cost oncologist isn't inherently concerning; a family physician with oncologist-level costs likely warrants review.

Explore specialty breakdowns in detail through our specialty directory, where you can compare metrics across all 250+ specialties in the dataset.