William Gillespie, M.D.
NPI 1538238118 · Psychiatry Physician · Glendora, CA
Enrolled with Medicare as Practitioner - Psychiatry · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Gillespie, M.D. is a Psychiatry Physician provider in Glendora, CA (NPI 1538238118).
Provider details
- NPI number
- 1538238118
- Entity type
- Individual
- Primary specialty
- Psychiatry PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- G81203 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
5,415 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
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 .
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) |
|---|---|---|
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 2,155 | $76 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 996 | $114 |
| Subsequent Nursing Facility Care With Straightforward Level of Medical Decision Making, Per Day, If Using Time, 20 Minutes Or More99308 | 612 | $73 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 599 | $97 |
| Initial Hospital Care With Straightforward Or Low-Level Medical Decision Making, If Using Time, at Least 55 Minutes99222 | 570 | $125 |
| Hospital Discharge Day Management, 30 Minutes Or Less |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 81 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Risperidone | 1,606 | 153 |
| Olanzapine | 1,353 | 148 |
| Divalproex Sodium | 1,330 | 168 |
| Escitalopram Oxalate | 1,245 | 123 |
| Trazodone Hcl | 1,243 | 126 |
| Quetiapine Fumarate | 1,225 | 138 |
| Benztropine Mesylate | 669 | 71 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$2,915 across 178 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-11-07
- Last updated
- 2013-02-28
Frequently asked questions
- What is William Gillespie's NPI number?
- William Gillespie's National Provider Identifier (NPI) is 1538238118, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Gillespie's specialty?
- William Gillespie is listed in the NPPES registry with a primary specialty of Psychiatry Physician (Allopathic & Osteopathic Physicians).
- Where is William Gillespie located?
- William Gillespie's practice location on file with NPPES is 510 S Grand Ave Ste 200, Glendora, CA 91741-4291.
- What is William Gillespie's phone number?
- The practice phone number listed in the NPPES registry for William Gillespie is (626) 914-1980.
- Does William Gillespie accept Medicare?
- William Gillespie is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Gillespie's NPI active?
- Yes — William Gillespie's NPI (1538238118) is active in the NPPES registry as of the last update on 2013-02-28.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.