William Liaw, M.D.
NPI 1912954611 · Internal Medicine Physician · Wellesley, MA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Liaw, M.D. is a Internal Medicine Physician provider in Wellesley, MA (NPI 1912954611).
Provider details
- NPI number
- 1912954611
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 154021 (MA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
20 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
1,488 Medicare services, 2024 (ranked within specialty)
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 methodology.
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 | 359 | $140 |
| Insertion of Needle Into Vein for Collection of Blood Sample36415 | 224 | $9 |
| Visit Complexity Inherent to Evaluation and Management Associated With Medical Care Services That Serve As the Continuing Focal Point for All Needed Health Care Services And/Or With Medical Care Services That Are Part of Ongoing Care Related to a Patient'SG2211 | 210 | $17 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 158 | $196 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 107 | $141 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 88 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 327 | 105 |
| Lorazepam | 183 | 41 |
| Rosuvastatin Calcium | 124 | 41 |
| Lisinopril | 107 | 30 |
| Metoprolol Succinate | 90 | 30 |
| Amlodipine Besylate | 87 | 32 |
| Gabapentin |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-05-28
- Last updated
- 2019-06-26
Frequently asked questions
- What is William Liaw's NPI number?
- William Liaw's National Provider Identifier (NPI) is 1912954611, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Liaw's specialty?
- William Liaw is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is William Liaw located?
- William Liaw's practice location on file with NPPES is 40 Walnut St Ste 102, Wellesley, MA 02481-2175.
- What is William Liaw's phone number?
- The practice phone number listed in the NPPES registry for William Liaw is (781) 943-3000.
- Does William Liaw accept Medicare?
- William Liaw is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Liaw's NPI active?
- Yes — William Liaw's NPI (1912954611) is active in the NPPES registry as of the last update on 2019-06-26.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.