Gregory Harmon, M.D.
NPI 1346347028 · Gastroenterology Physician · Harbor City, CA
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Gregory Harmon, M.D. is a Gastroenterology Physician provider in Harbor City, CA (NPI 1346347028).
Provider details
- NPI number
- 1346347028
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- A79243 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
675 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 211 | $138 |
| Biopsy of Large Bowel Using a Flexible Endoscope45380 | 91 | $92 |
| Removal of Polyps Or Growths of Large Bowel Using an Endoscope With Mechanical Snare45385 | 80 | $237 |
| Biopsy of Esophagus, Stomach, And/Or Upper Small Bowel Using a Flexible Endoscope43239 | 72 | $81 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 66 | $99 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 16 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Omeprazole | 214 | 73 |
| Pantoprazole Sodium | 173 | 51 |
| Famotidine | 131 | 48 |
| Linaclotidebrand: Linzess | 33 | — |
| Sodium Chloride/Nahco3/Kcl/Pegbrand: Peg 3350-Electrolyte | 30 | 29 |
| Mesalamine | 22 | — |
| Peg3350/Sod Sulf,bicarb,cl/Kclbrand: Gavilyte-G | 19 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$17 across 1 record (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-09-17
- Last updated
- 2025-12-02
- Certified
- 2025-12-02
Frequently asked questions
- What is Gregory Harmon's NPI number?
- Gregory Harmon's National Provider Identifier (NPI) is 1346347028, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Gregory Harmon's specialty?
- Gregory Harmon is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is Gregory Harmon located?
- Gregory Harmon's practice location on file with NPPES is 25825 Vermont Ave, Harbor City, CA 90710-3518.
- What is Gregory Harmon's phone number?
- The practice phone number listed in the NPPES registry for Gregory Harmon is (310) 325-5111.
- Does Gregory Harmon accept Medicare?
- Gregory Harmon is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Gregory Harmon's NPI active?
- Yes — Gregory Harmon's NPI (1346347028) is active in the NPPES registry as of the last update on 2025-12-02.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.