William Halsey, MD
NPI 1295775237 · Anesthesiology Physician · San Francisco, CA
Enrolled with Medicare as Practitioner - Anesthesiology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Halsey, MD is a Anesthesiology Physician provider in San Francisco, CA (NPI 1295775237).
Provider details
- NPI number
- 1295775237
- Entity type
- Individual
- Primary specialty
- Anesthesiology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- C37471 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
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
105 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) |
|---|---|---|
| Anesthesia for Other Procedure on Lower Spine00630 | 56 | $210 |
| Anesthesia for Other Procedure on Upper Spine00600 | 29 | $247 |
| Anesthesia for Closed Procedure on Pubic Bone Or Pelvic Joint01160 | 20 | $122 |
Typical Medicare-allowed amounts for these services range $122–$247 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-06-07
- Last updated
- 2007-07-11
Frequently asked questions
- What is William Halsey's NPI number?
- William Halsey's National Provider Identifier (NPI) is 1295775237, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Halsey's specialty?
- William Halsey is listed in the NPPES registry with a primary specialty of Anesthesiology Physician (Allopathic & Osteopathic Physicians).
- Where is William Halsey located?
- William Halsey's practice location on file with NPPES is 3700 California St, San Francisco, CA 94118-1618.
- What is William Halsey's phone number?
- The practice phone number listed in the NPPES registry for William Halsey is (415) 719-0000.
- Does William Halsey accept Medicare?
- William Halsey is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Halsey's NPI active?
- Yes — William Halsey's NPI (1295775237) is active in the NPPES registry as of the last update on 2007-07-11.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.