William Maher, M.D.
NPI 1477550739 · Gastroenterology Physician · Somersworth, NH
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Maher, M.D. is a Gastroenterology Physician provider in Somersworth, NH (NPI 1477550739).
Provider details
- NPI number
- 1477550739
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 10956 (NH)
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
1,172 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 | 200 | $125 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 132 | $77 |
| Colorectal Cancer Screening; Colonoscopy on Individual at High RiskG0105 | 115 | $177 |
| Initial Hospital Care With Straightforward Or Low-Level Medical Decision Making, If Using Time, at Least 55 Minutes99222 | 94 | $126 |
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More99204 | 92 | $165 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 17 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Omeprazole | 192 | 60 |
| Famotidine | 166 | 49 |
| Pantoprazole Sodium | 115 | 35 |
| Ursodiol | 60 | — |
| Colestipol Hcl | 55 | 20 |
| Sucralfate | 30 | — |
| Dicyclomine Hcl | 22 | — |
| Mesalamine | 22 | — |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$128 across 6 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
- 2005-07-01
- Last updated
- 2011-09-30
Frequently asked questions
- What is William Maher's NPI number?
- William Maher's National Provider Identifier (NPI) is 1477550739, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Maher's specialty?
- William Maher is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is William Maher located?
- William Maher's practice location on file with NPPES is 21 Clark Way, Somersworth, NH 03878-4401.
- What is William Maher's phone number?
- The practice phone number listed in the NPPES registry for William Maher is (603) 692-2228.
- Does William Maher accept Medicare?
- William Maher is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Maher's NPI active?
- Yes — William Maher's NPI (1477550739) is active in the NPPES registry as of the last update on 2011-09-30.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.