Jeffrey Mark, M.D.
NPI 1487603155 · Gastroenterology Physician · Turlock, CA
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Jeffrey Mark, M.D. is a Gastroenterology Physician provider in Turlock, CA (NPI 1487603155).
Provider details
- NPI number
- 1487603155
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- License
- G83524 (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
20 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
838 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 | 670 | $137 |
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More99204 | 69 | $175 |
| Biopsy of Large Bowel Using a Flexible Endoscope45380 | 50 | $200 |
| Biopsy of Esophagus, Stomach, And/Or Upper Small Bowel Using a Flexible Endoscope43239 | 33 | $116 |
| Removal of Polyps Or Growths of Large Bowel Using an Endoscope With Mechanical Snare45385 | 16 | $259 |
Typical Medicare-allowed amounts for these services range $116–$259 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 15 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Sodium, Potassium,mag Sulfatesbrand: Sod Sulf-Potass Sulf-Mag Sulf | 68 | 67 |
| Omeprazole | 67 | 20 |
| Famotidine | 40 | 19 |
| Pantoprazole Sodium | 38 | — |
| Sucralfate | 28 | 17 |
| Linaclotidebrand: Linzess | 27 | — |
| Lansoprazole | 23 | — |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$348 across 12 records (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
- 2006-05-09
- Last updated
- 2007-07-08
Frequently asked questions
- What is Jeffrey Mark's NPI number?
- Jeffrey Mark's National Provider Identifier (NPI) is 1487603155, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Jeffrey Mark's specialty?
- Jeffrey Mark is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is Jeffrey Mark located?
- Jeffrey Mark's practice location on file with NPPES is 2101 Geer Rd, Turlock, CA 95382-2454.
- What is Jeffrey Mark's phone number?
- The practice phone number listed in the NPPES registry for Jeffrey Mark is (209) 669-5000.
- Does Jeffrey Mark accept Medicare?
- Jeffrey Mark is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Jeffrey Mark's NPI active?
- Yes — Jeffrey Mark's NPI (1487603155) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.