How to Find Gastroenterologists by Zip Code
Data sourced from live CMS NPI Registry API v2.1 queries, run June 13, 2026. All provider counts are real API responses, not estimates. Raw query results are available for download. See methodology below.
taxonomy_description=Gastroenterology. Two zero-result traps: GI returns nothing (confirmed June 13, 2026), and Gastrointestinal also returns nothing. The hepatology gotcha: hepatologists are registered under a completely separate CMS taxonomy string — a Gastroenterology query does not include them. This guide covers real counts from 9 markets, the subspecialty taxonomy table with NUCC codes, a Memphis dataset drill-down, and radius guidance for a specialty that concentrates heavily around hospital endoscopy infrastructure.
taxonomy_description=GI → 0 records. taxonomy_description=Gastrointestinal → 0 records. Both confirmed June 13, 2026. The CMS taxonomy system does not recognize either abbreviation. The only working string is Gastroenterology. Additionally, Hepatology is a fully separate CMS taxonomy — hepatologists do not appear in a standard Gastroenterology query and require a dedicated second query.
Gastroenterology in the NPI registry: real counts from 9 markets
We queried the CMS NPI API v2.1 on June 13, 2026 with taxonomy_description=Gastroenterology.
| Market | Query scope | NPI records returned | At 200-record cap? |
|---|---|---|---|
| New York, NY | City filter | 200+ | Yes (more exist) |
| Los Angeles, CA | City filter | 200+ | Yes (more exist) |
| Chicago, IL | City filter | 200+ | Yes (more exist) |
| Houston, TX | City filter | 200+ | Yes (more exist) |
| Phoenix, AZ | City filter | 200+ | Yes (more exist) |
| Nashville, TN | City filter | 167 | No (complete) |
| Memphis, TN | City filter | 79 | No (complete) |
| Vermont (statewide) | State filter | 62 | No (complete) |
| Wyoming (statewide) | State filter | 23 | No (complete) |
Source: CMS NPI Registry API v2.1, taxonomy_description=Gastroenterology, limit=200. Queried June 13, 2026. Counts include both individual providers (NPI-1) and organization records (NPI-2) such as GI group practices. Hepatologists not included; they require a separate Hepatology query.
Gastroenterology subspecialties: the taxonomy table
| Subspecialty | taxonomy_description value | NUCC code | National June 2026 |
|---|---|---|---|
| General gastroenterologist | Gastroenterology |
207RG0100X | 200+ (capped) |
| Hepatologist (liver disease) | Hepatology |
207RI0008X | 200+ (capped) — separate query required |
| Transplant hepatologist | Transplant Hepatology |
207RT0003X | 200+ (capped) — separate query required |
| Pediatric gastroenterologist | Pediatric Gastroenterology |
208000000X | 200+ (capped) — separate query required |
| "GI" (abbreviation) | Invalid — returns 0 | None | 0 — use Gastroenterology |
| "Gastrointestinal" | Invalid — returns 0 | None | 0 — use Gastroenterology |
How to search for gastroenterologists by zip code (5 steps)
Choose your search method
- NPI registry directly at npiregistry.cms.hhs.gov — free, no account, city or state filter only. No radius search.
- getdork Physician Search — same CMS API with zip-radius filtering, correct taxonomy pre-mapped, CSV export. Search gastroenterologists by ZIP →
Use the correct taxonomy string: Gastroenterology
The exact API parameter is taxonomy_description=Gastroenterology. Neither "GI" nor
"Gastrointestinal" works. The numeric NUCC code 207RG0100X is silently ignored.
In getdork, selecting Gastroenterology from the dropdown sends the correct string automatically.
Add a separate Hepatology query if hepatologists are targets
Hepatologists appear under the CMS taxonomy string Hepatology and will not be
returned by a Gastroenterology query. In Memphis, only 1 of 79 GI records showed
transplant hepatology. Nationally, Hepatology and Transplant Hepatology both returned 200+
records. For products targeting HBV/HCV, NASH/MASH, or liver transplant programs, run
a dedicated Hepatology or Transplant+Hepatology query separately.
Set radius with endoscopy infrastructure in mind
Gastroenterologists cluster around hospitals and ambulatory surgery centers with endoscopy suites. In rural areas like Wyoming (23 statewide), the few GI physicians that exist are concentrated in one or two cities. A 75–100 mile radius is realistic for rural Wyoming territory planning. For Memphis and similar mid-metros, 25 miles captures the city's GI group practices and hospital-employed physicians.
Export to CSV (Pro) and review the taxonomy column
Pro users export the complete result set. Column headers: NPI, Name, Credential, Address, City, State, Zip, Phone, Entity Type. The taxonomy description column shows whether each record is general gastroenterology, transplant hepatology, or pediatric gastroenterology — segment before routing to product-specific rep assignments.
Direct API queries
# Gastroenterologists in Memphis, TN — returned 79 records (June 2026) https://npiregistry.cms.hhs.gov/api/? version=2.1 &taxonomy_description=Gastroenterology &city=Memphis &state=TN &limit=200 # FAILS — GI abbreviation returns zero results https://npiregistry.cms.hhs.gov/api/? version=2.1 &taxonomy_description=GI &city=Memphis &state=TN &limit=200 # Hepatologists — separate taxonomy, 200+ nationally https://npiregistry.cms.hhs.gov/api/? version=2.1 &taxonomy_description=Hepatology &state=TN &limit=200 # Transplant hepatologists — another separate string https://npiregistry.cms.hhs.gov/api/? version=2.1 &taxonomy_description=Transplant+Hepatology &state=TN &limit=200
Radius guidance for gastroenterology territories
| Market type | Recommended starting radius | Rationale |
|---|---|---|
| Dense urban (NYC, Chicago, LA, Houston) | 10–15 miles | All four metros hit the 200-cap; GI density is high in cities with major academic medical centers and ambulatory surgery chains |
| Mid-metro (Memphis, Nashville, Phoenix) | 25 miles | Memphis: 79 (complete); Nashville: 167 (complete); Phoenix: 200+ (capped). 25 miles captures GI group practices and hospital-employed physicians. |
| Rural (Wyoming, Vermont) | 75–100 miles | Wyoming: 23 statewide; Vermont: 62 statewide. GI is procedural infrastructure-dependent — providers concentrate in cities with endoscopy suites. Rural gaps are large. |
getdork sends
taxonomy_description=Gastroenterology — not "GI" —
and handles the zip-radius math. The exported CSV includes the taxonomy column so you can
separate general GI, transplant hepatology, and pediatric GI before your CRM import.
Free to preview; Pro for the full list and CSV export.
Search gastroenterologists by ZIP code — free →
Frequently asked questions
Why does "GI" return zero results in the NPI registry?
The CMS NPI API performs an exact-match or prefix-match on the taxonomy_description field.
"GI" is not a recognized CMS taxonomy string. Neither is "Gastrointestinal" — both
confirmed to return zero results on June 13, 2026. The only working string is
Gastroenterology. In any automated pipeline where someone abbreviates the query,
this produces a silent zero-result failure with no error message.
Are hepatologists included in a Gastroenterology NPI query?
No. Hepatology (NUCC 207RI0008X) is a fully separate CMS taxonomy string. A
standard Gastroenterology query does not return hepatologists. In Memphis, only 1 of 79
gastroenterology records showed Transplant Hepatology as primary taxonomy. For products
targeting HBV/HCV antivirals, NASH/MASH therapies, or liver transplant programs, run a
dedicated Hepatology query separately.
How clean is the gastroenterology NPI dataset compared to other specialties?
Gastroenterology is one of the cleaner specialty datasets. In Memphis (79 records, June 2026), 72 of 79 records had Internal Medicine, Gastroenterology as primary taxonomy — a 91% signal rate. The remaining 7 included noise records (Anesthesiology, Family Medicine, RN). By comparison, a cardiology query in Memphis showed roughly 14% non-primary records. For a rep building an outpatient GI call list, a raw Gastroenterology query needs minimal additional filtering.
What is the NPI credential breakdown for gastroenterologists?
In the Memphis dataset of 79 records (June 2026): 31 showed "M.D.," 29 showed "MD" (same degree, different formatting variant), 4 "M.D," 2 D.O., 2 DO. The credential inconsistency is a CMS data entry artifact — "M.D." and "MD" are the same licensure. Nine NPI-2 organization records had no credential field (expected for group practices). Count organization records separately from individual physicians when building call metrics.
Why is Wyoming's gastroenterology count so low compared to neurology?
Wyoming gastroenterology returned 23 statewide; Wyoming neurology returned 58. GI is a procedural specialty requiring endoscopy suite infrastructure, which concentrates providers at larger hospital-affiliated centers. Neurology has broader distribution because outpatient neurology clinics require lighter capital equipment. For a GI call list in Wyoming, a 75–100 mile radius from Casper or Cheyenne is more realistic than the 50-mile starting point appropriate for neurology.
What pharma and device products use a gastroenterologist call list?
IBD biologics (adalimumab, infliximab, ustekinumab, vedolizumab, risankizumab, mirikizumab), IBD small molecules (ozanimod, upadacitinib), proton pump inhibitors and H. pylori eradication regimens, GLP-1 agonists for NASH/MASH, endoscopy capital equipment (colonoscopes, enteroscopes, EUS systems, ERCP accessories), single-use endoscopy consumables, hemostasis products, and screening colonoscopy quality monitoring tools. For hepatology-adjacent accounts: HBV/HCV antivirals and liver fibrosis non-invasive diagnostics.
Data methodology
All provider counts come from direct queries to the CMS NPI Registry API v2.1, run on
June 13, 2026. We used taxonomy_description=Gastroenterology and limit=200.
No authentication required. Result_count reflects records returned on that page; when equal
to 200 the actual total exceeds 200. Counts below 200 are exact.
We confirmed: GI → 0 results; Gastrointestinal → 0 results.
Hepatology, Transplant Hepatology, and Pediatric Gastroenterology
each returned 200+ nationally (separate taxonomy strings).
Raw responses: npi-gastroenterology-memphis-tn-raw.json, npi-gastroenterology-wyoming-raw.json. Collection script: _data/npi-counts-gastroenterology.ps1.
Related guides
- How to search the NPI registry (full guide) — complete API reference and the taxonomy_description quirk explained in detail.
- What is an NPI number and what can you look up? — NPI types, fields, and data freshness.
- How to find physicians by specialty and state — state-level NPI searches across specialties.
- How to find neurologists by zip code — another specialty where common terms (Neurologist) return zero results.
- How to find rheumatologists by zip code — a sparse specialty with critical rural radius guidance.