Mark Allen Williams, PMHNP-BC
NPI 1023786225ActiveIndividual· Nurse Practitioner, Psych/Mental Health· Mesa, AZ
Nurse Practitioner, Psych/Mental Health (PMHNP-BC) with Denova Collaborative Health LLC, practicing in Mesa, Arizona. Their prescriptions cost Medicare Part D more than their services did: $98,821 for 1,346 claims, against $5,425 paid for services in 2024. Iti, Inc. (D/B/A Intra-Cellular Therapies, Inc.) was the largest of 6 companies reporting payments in 2025, $538.61 in all, mostly food and beverage.
Overview
| NPI | 1023786225 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | PMHNP-BC |
| Sole proprietor | No |
| NPI issued | Sep 1, 2021 |
| Last updated in NPPES | Dec 12, 2025 |
| Certified by provider | Dec 12, 2025 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Nurse Practitioner, Psych/Mental Health Primary | 363LP0808X | AP-263407 | AZ |
| Nurse Practitioner, Psych/Mental Health | 363LP0808X | RNP263407 | AZ |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Oct 9, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 10, 2026 | No match | — |
| New York OMIG · Nov 10, 2026 | No match | — |
| Ohio Medicaid · Nov 10, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 10, 2026 | No match | — |
| Washington HCA · Nov 10, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Nurse Practitioner (AZ) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 19 |
|---|---|
| Services billed | 110 across 6 procedure codes |
| Paid by Medicare | $5,425 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,346 · 2,033 30-day fills |
|---|---|
| Patients | 80 |
| Total drug cost | $98,821 |
| Generic share | 96% of claims |
Education and affiliations
| Graduation year | 2021 |
|---|---|
| Medicare specialty | Nurse Practitioner |
| Telehealth | Offers telehealth |
Medical group
- Denova Collaborative Health LLCPhoenix, AZ · 157 clinicians
Industry payments (Open Payments)
- 2025$538.61 · 27 payments from 6 companies
- 2024$573.60 · 24 payments from 11 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Iti, Inc. (D/B/A Intra-Cellular Therapies, Inc.) | $348.31 | 18 |
| E.R. Squibb & Sons, L.L.C. | $74.60 | 4 |
| Alkermes, Inc. | $57.25 | 2 |
| Vanda Pharmaceuticals Inc. | $22.87 | 1 |
| Braeburn Inc. | $22.09 | 1 |
What the 2025 payments were for
- Food and Beverage$538.61 · 27 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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