Michael Steven Santillan, PA-C, CAQ-PSYCH
NPI 1861139628ActiveIndividual· Physician Assistant, Medical· Mission Viejo, CA
Physician Assistant, Medical (PA-C, CAQ-PSYCH) with Pacific Neuropsychiatric Specialists Inc, practicing in Mission Viejo, California. Their prescriptions cost Medicare Part D more than their services did: $527,716 for 1,578 claims, against $19,764 paid for services in 2024. Vanda Pharmaceuticals Inc. was the largest of 14 companies reporting payments in 2025, $875.53 in all, mostly food and beverage.
Overview
| NPI | 1861139628 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | PA-C, CAQ-PSYCH |
| Sole proprietor | No |
| NPI issued | May 13, 2022 |
| Last updated in NPPES | Sep 30, 2025 |
| Certified by provider | Sep 30, 2025 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Physician Assistant, Medical Primary | 363AM0700X | PA61412 | CA |
| Clinical Nurse Specialist, Psych/Mental Health | 364SP0808X | PA61412 | CA |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Nov 10, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 11, 2026 | No match | — |
| New York OMIG · Nov 11, 2026 | No match | — |
| Ohio Medicaid · Nov 11, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 11, 2026 | No match | — |
| Washington HCA · Nov 11, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Physician Assistant (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 37 |
|---|---|
| Services billed | 339 across 8 procedure codes |
| Paid by Medicare | $19,764 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,578 · 1,993 30-day fills |
|---|---|
| Patients | 97 |
| Total drug cost | $527,716 |
| Generic share | 88% of claims |
Education and affiliations
| Graduation year | 2022 |
|---|---|
| Medicare specialty | Physician Assistant |
| Telehealth | Offers telehealth |
Medical group
- Pacific Neuropsychiatric Specialists IncCorona, CA · 72 clinicians
Industry payments (Open Payments)
- 2025$875.53 · 36 payments from 14 companies
- 2024$4,820 · 191 payments from 20 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Vanda Pharmaceuticals Inc. | $157.36 | 5 |
| Janssen Pharmaceuticals, Inc | $126.51 | 4 |
| Alkermes, Inc. | $94.72 | 4 |
| Abbvie Inc. | $85.39 | 5 |
| Supernus Pharmaceuticals, Inc. | $69.09 | 3 |
What the 2025 payments were for
- Food and Beverage$875.53 · 36 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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