William Mcallister, M.D.
NPI 1821072646 · Internal Medicine Physician · Corte Madera, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Mcallister, M.D. is a Internal Medicine Physician provider in Corte Madera, CA (NPI 1821072646).
Provider details
- NPI number
- 1821072646
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- G18899 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
20 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
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.
Practice location
Mailing address
Registry dates
- Enumerated
- 2005-12-05
- Last updated
- 2017-02-13
Frequently asked questions
- What is William Mcallister's NPI number?
- William Mcallister's National Provider Identifier (NPI) is 1821072646, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Mcallister's specialty?
- William Mcallister is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is William Mcallister located?
- William Mcallister's practice location on file with NPPES is 21 Tamal Vista Blvd, Corte Madera, CA 94925-1130.
- What is William Mcallister's phone number?
- The practice phone number listed in the NPPES registry for William Mcallister is (415) 924-5010.
- Does William Mcallister accept Medicare?
- William Mcallister is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Mcallister's NPI active?
- Yes — William Mcallister's NPI (1821072646) is active in the NPPES registry as of the last update on 2017-02-13.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.