William Holder, M.D.
NPI 1205216728 · Emergency Medicine Physician · South San Francisco, CA
Enrolled with Medicare as Practitioner - Emergency Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Holder, M.D. is a Emergency Medicine Physician provider in South San Francisco, CA (NPI 1205216728).
Provider details
- NPI number
- 1205216728
- Entity type
- Individual
- Primary specialty
- Emergency Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- MD-20152 (HI)
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 tenure28% of score
11 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
22 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) |
|---|---|---|
| Emergency Department Visit With Moderate Level of Medical Decision Making99284 | 22 | $128 |
Typical Medicare-allowed amounts for these services range $128–$128 (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.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 8 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Ibuprofen | 25 | 24 |
| Oxycodone Hcl | 22 | 22 |
| Amoxicillin/Potassium Clavbrand: Amoxicillin-Clavulanate Potass | 20 | 20 |
| Naproxen | 20 | 20 |
| Cefpodoxime Proxetil | 17 | 17 |
| Dexamethasone | 14 | 14 |
| Ondansetronbrand: Ondansetron Odt | 13 | 13 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2015-06-01
- Last updated
- 2025-02-20
- Certified
- 2025-02-20
Frequently asked questions
- What is William Holder's NPI number?
- William Holder's National Provider Identifier (NPI) is 1205216728, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Holder's specialty?
- William Holder is listed in the NPPES registry with a primary specialty of Emergency Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is William Holder located?
- William Holder's practice location on file with NPPES is 1200 El Camino Real, South San Francisco, CA 94080-3208.
- What is William Holder's phone number?
- The practice phone number listed in the NPPES registry for William Holder is (650) 742-2000.
- Does William Holder accept Medicare?
- William Holder is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Holder's NPI active?
- Yes — William Holder's NPI (1205216728) is active in the NPPES registry as of the last update on 2025-02-20.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.