William Marek, PH.D.
NPI 1851560544 · Psychologist · San Ramon, CA
Enrolled with Medicare as Practitioner - Clinical Psychologist · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Marek, PH.D. is a Psychologist provider in San Ramon, CA (NPI 1851560544).
Provider details
- NPI number
- 1851560544
- Entity type
- Individual
- Primary specialty
- PsychologistBehavioral Health & Social Service Providers
- Credential
- PH.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- PSY 14791 (CA)
Specialties & taxonomies
Behavioral Health & Social Service Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
18 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
2,042 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) |
|---|---|---|
| Psychotherapy, 30 Minutes90832 | 1,750 | $83 |
| Evaluation of Psychological Test, First Hour96130 | 185 | $113 |
| Psychiatric Diagnostic Evaluation90791 | 107 | $182 |
Typical Medicare-allowed amounts for these services range $83–$182 (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
- 2008-02-27
- Last updated
- 2008-02-27
Frequently asked questions
- What is William Marek's NPI number?
- William Marek's National Provider Identifier (NPI) is 1851560544, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Marek's specialty?
- William Marek is listed in the NPPES registry with a primary specialty of Psychologist (Behavioral Health & Social Service Providers).
- Where is William Marek located?
- William Marek's practice location on file with NPPES is 105 Reflections Dr, San Ramon, CA 94583-4709.
- What is William Marek's phone number?
- The practice phone number listed in the NPPES registry for William Marek is (925) 275-0294.
- Does William Marek accept Medicare?
- William Marek is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Marek's NPI active?
- Yes — William Marek's NPI (1851560544) is active in the NPPES registry as of the last update on 2008-02-27.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.