taxonomy_description=Radiation+Oncology.
No auth required. result_count=200 means page cap hit; true total is higher.
Raw data: npi-counts-radiation-oncology.json ·
Memphis raw ·
Vermont raw ·
Script: npi-counts-radiation-oncology.ps1
taxonomy_description=Radiation+Oncology (NUCC 2085R0001X).
"Radiation Oncologist" returns zero. "Radiation Therapy" returns 192 records — radiation therapists and
treatment centers, not MD physicians. This is a sparse specialty; query statewide in rural markets.
taxonomy_description=Radiation+Oncologist returns 0 results.
The intuitive alternative — Radiation+Therapy — returns 192 records nationally,
but almost entirely radiation therapists (NUCC: Radiologic Technologist, Radiation Therapy) and
radiation treatment centers (NPI-2 organizations). A device rep selling to the MD radiation oncologist
who prescribes and supervises treatment must use Radiation+Oncology, not "Radiation Therapy."
The distinction is physician vs. technologist — an entirely different call list.
Queried 2026-06-13 using taxonomy_description=Radiation+Oncology.
This is a sparse specialty — most markets return complete counts, not capped results.
| Market | Records returned | Notes |
|---|---|---|
| New York, NY | 200+ | Capped — major academic and community cancer centers |
| Los Angeles, CA | 200+ | Capped |
| Chicago, IL | 200+ | Capped |
| Houston, TX | 200+ | Capped — includes MD Anderson satellite network |
| Nashville, TN | 90 | Complete count for city proper |
| Phoenix, AZ | 79 | Complete count |
| Memphis, TN | 34 | Complete count — see drill-down below |
| Vermont (statewide) | 26 | Complete statewide count — see drill-down |
| Wyoming (statewide) | 21 | Complete statewide count — very sparse |
Source: npi-counts-radiation-oncology.json, queried 2026-06-13.
These two strings look similar but return entirely different populations:
| String | Returns | National count | Who they are |
|---|---|---|---|
Radiation Oncology |
MD radiation oncologists | 200+ (capped) | Physicians who prescribe and supervise radiation treatment — NUCC 2085R0001X |
Radiation Therapy |
Radiation therapists + treatment centers | 192 | Allied health technologists (operate the linear accelerator) + NPI-2 treatment facilities — not prescribing MDs |
Radiation Oncologist |
0 results | 0 | Not a NUCC taxonomy code — returns nothing |
Source: npi-counts-radiation-oncology.json, queried 2026-06-13.
https://npiregistry.cms.hhs.gov/api/?version=2.1
&taxonomy_description=Radiation+Oncology
&city=Memphis&state=TN&limit=200The NUCC code is 2085R0001X. Note that the CMS API sometimes returns a null desc field for this code —
that is an API behavior, not a data error. The record count is correct.
Add &enumeration_type=NPI-1 to isolate individual providers from treatment center organization records.
In Vermont, this reduces 26 records to 20 practicing radiation oncologists.
Radiation oncologists are anchored to hospital-based linear accelerators — they do not maintain dispersed office practices. In markets with fewer than 30 statewide providers (Wyoming, Vermont, most rural states), query statewide and use the complete list rather than filtering by radius.
Radiation Oncology, handles NPI-1/NPI-2 filtering, and exports
a CRM-ready CSV — no manual taxonomy hunting required.Radiation oncology is among the most geographically concentrated medical specialties. Linear accelerators are capital equipment — they do not travel, and neither do the physicians who operate them.
Radiation Therapy (192 records nationally) returns radiation therapists — allied health technologists
who operate treatment equipment — plus radiation treatment centers (NPI-2 organizations). These are not
the MD radiation oncologists a device or pharma rep needs. The correct string is
Radiation Oncology (2085R0001X), which returns the physician specialists who prescribe
and supervise treatment.
Radiation oncologists enumerate under NUCC code 2085R0001X with
taxonomy_description=Radiation+Oncology. The CMS NPI API v2.1 sometimes returns this
code with a null description field — that is an API behavior, not a data error. The code is correct
and returns MD radiation oncologists when queried by taxonomy_description string.
"Radiation Oncologist" is a professional title. The NPI registry uses NUCC taxonomy descriptions, not titles. The API performs an exact-match or prefix search on the taxonomy_description field. "Radiation Oncologist" matches nothing in the taxonomy table; "Radiation Oncology" returns the correct physician records.
Wyoming statewide returned 21 radiation oncologists on 2026-06-13; Vermont returned 26. These are small, complete call lists. For any state outside major metro corridors, query by state rather than ZIP radius — the total count is manageable and radius math doesn't add value when there are fewer than 30 providers in the state. For mid-size metros, 50 miles; for large urban markets, 15–25 miles covers the major cancer centers.
No. Radiation Oncology is a separate NUCC taxonomy from Hematology & Oncology and Medical Oncology. A rep building a comprehensive oncology territory needs Radiation Oncology as a separate query pass. Radiation oncologists trained through Radiology, not Internal Medicine, so their NUCC parent specialty is different entirely.
Radiation oncologists are the prescribers and clinical leads for linear accelerators, stereotactic radiosurgery systems, brachytherapy equipment, treatment planning software, and radiation dosimetry tools. They also make formulary-adjacent decisions for radiosensitizing agents. A verified NPI call list for this specialty supports capital equipment sales cycles, clinical adoption programs, and academic center account planning — all contexts where the right contact is the MD radiation oncologist, not the radiation therapist who operates the machine.