William Hasler, MD
NPI 1346322872 · Gastroenterology Physician · Ann Arbor, MI
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Hasler, MD is a Gastroenterology Physician provider in Ann Arbor, MI (NPI 1346322872).
Provider details
- NPI number
- 1346322872
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 4301404025 (MI)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
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
2 documented practice locations
- Medicare service volume (vs. specialty peers)25% of score
622 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 Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 111 | $87 |
| Biopsy of Large Bowel Using a Flexible Endoscope45380 | 83 | $125 |
| Office Or Other Outpatient Visit for the Evaluation and Management of Established Patient That May Not Require Presence of Healthcare Professional99211 | 78 | $22 |
| Moderate Sedation Services Provided By the Same Physician Or Other Qualified Health Care Professional Performing a Gastrointestinal Endoscopic Service That Sedation Supports, Requiring the Presence of an Independent Trained Observer to Assist in the MonitoG0500 | 78 | $5 |
| Biopsy of Esophagus, Stomach, And/Or Upper Small Bowel Using a Flexible Endoscope43239 | 64 | $108 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 13 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Famotidine | 66 | — |
| Gentamicin Sulfate | 53 | — |
| Mirtazapine | 36 | — |
| Pantoprazole Sodium | 30 | — |
| Rifaximinbrand: Xifaxan | 23 | — |
| Peg3350/Sod Sulf,bicarb,cl/Kclbrand: Gavilyte-G | 17 | 15 |
| Ondansetronbrand: Ondansetron Odt | 15 | — |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$179 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
Additional practice locations (1)
- 13400 E Shea BlvdScottsdale, AZ 85259-5452Phone: (480) 301-8000
Registry dates
- Enumerated
- 2006-10-20
- Last updated
- 2021-10-18
- Certified
- 2021-10-18
Frequently asked questions
- What is William Hasler's NPI number?
- William Hasler's National Provider Identifier (NPI) is 1346322872, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Hasler's specialty?
- William Hasler is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is William Hasler located?
- William Hasler's practice location on file with NPPES is 1500 E Medical Center Dr, Ann Arbor, MI 48109-5000.
- What is William Hasler's phone number?
- The practice phone number listed in the NPPES registry for William Hasler is (734) 936-4000.
- Does William Hasler accept Medicare?
- William Hasler is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Hasler's NPI active?
- Yes — William Hasler's NPI (1346322872) is active in the NPPES registry as of the last update on 2021-10-18.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.