William Marsteller, M.D.
NPI 1992917504 · Gastroenterology Physician · Charleston, SC
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Marsteller, M.D. is a Gastroenterology Physician provider in Charleston, SC (NPI 1992917504).
Provider details
- NPI number
- 1992917504
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 32824 (SC)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Student, Health Care
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
1,293 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 | 272 | $117 |
| Biopsy of Large Bowel Using a Flexible Endoscope45380 | 206 | $78 |
| Biopsy of Esophagus, Stomach, And/Or Upper Small Bowel Using a Flexible Endoscope43239 | 190 | $86 |
| Removal of Polyps Or Growths of Large Bowel Using an Endoscope With Mechanical Snare45385 | 186 | $224 |
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More99204 | 143 | $155 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 35 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Pantoprazole Sodium | 446 | 160 |
| Omeprazole | 259 | 86 |
| Famotidine | 213 | 82 |
| Dexlansoprazolebrand: Dexlansoprazole Dr | 84 | 15 |
| Sod Sulf/Pot Chloride/Mag Sulfbrand: Sutab | 68 | 68 |
| Sucralfate | 65 | 31 |
| Peg3350/Sod Sulf,bicarb,cl/Kclbrand: Gavilyte-C | 64 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$189 across 4 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
- 2007-05-04
- Last updated
- 2020-05-07
- Certified
- 2020-05-07
Frequently asked questions
- What is William Marsteller's NPI number?
- William Marsteller's National Provider Identifier (NPI) is 1992917504, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Marsteller's specialty?
- William Marsteller is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is William Marsteller located?
- William Marsteller's practice location on file with NPPES is 1962 Charlie Hall Blvd., Charleston, SC 29414.
- What is William Marsteller's phone number?
- The practice phone number listed in the NPPES registry for William Marsteller is (843) 722-8000.
- Does William Marsteller accept Medicare?
- William Marsteller is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Marsteller's NPI active?
- Yes — William Marsteller's NPI (1992917504) is active in the NPPES registry as of the last update on 2020-05-07.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.