William Stassen, M.D.
NPI 1548245079 · Gastroenterology Physician · Austin, TX
William Stassen, M.D. is a Gastroenterology Physician provider in Austin, TX (NPI 1548245079).
Provider details
- NPI number
- 1548245079
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- G7893 (TX)
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
556 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) |
|---|---|---|
| Biopsy of Large Bowel Using a Flexible Endoscope45380 | 137 | $159 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 129 | $124 |
| Biopsy of Esophagus, Stomach, And/Or Upper Small Bowel Using a Flexible Endoscope43239 | 78 | $77 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 58 | $89 |
| Removal of Polyps Or Growths of Large Bowel Using an Endoscope With Mechanical Snare45385 | 41 | $244 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 14 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Omeprazole | 360 | 126 |
| Pantoprazole Sodium | 40 | 18 |
| Dicyclomine Hcl | 36 | 15 |
| Sodium Chloride/Nahco3/Kcl/Pegbrand: Peg 3350-Electrolyte | 36 | 33 |
| Esomeprazole Magnesium | 31 | — |
| Peg3350/Sod Sul/Nacl/Kcl/Asb/Cbrand: Plenvu | 30 | 30 |
| Hydrocortisone | 24 | 11 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$1,153 across 60 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
- 2005-12-07
- Last updated
- 2013-01-08
Frequently asked questions
- What is William Stassen's NPI number?
- William Stassen's National Provider Identifier (NPI) is 1548245079, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Stassen's specialty?
- William Stassen is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is William Stassen located?
- William Stassen's practice location on file with NPPES is 8015 Shoal Creek Blvd Ste 118, Austin, TX 78757-8052.
- What is William Stassen's phone number?
- The practice phone number listed in the NPPES registry for William Stassen is (512) 244-2273.
- Is William Stassen's NPI active?
- Yes — William Stassen's NPI (1548245079) is active in the NPPES registry as of the last update on 2013-01-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.