Mary Parker Johnstone
NPI 1639810807ActiveIndividual· Physician Assistant· Cambridge, MA
Physician Assistant in Cambridge, Massachusetts, trained at University of Tennessee, Hsc, College of Medicine (class of 2021). Part D covered 223 prescriptions written in 2024, 71% of them generic. Janssen Biotech, Inc. was the largest of 2 companies reporting payments in 2025, $714.92 in all, mostly food and beverage.
Overview
| NPI | 1639810807 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Sole proprietor | Yes |
| NPI issued | Apr 5, 2022 |
| Last updated in NPPES | May 5, 2023 |
| Certified by provider | May 5, 2023 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Physician Assistant Primary | 363A00000X | PA9335 | MA |
| Orthopaedic Surgery | 207X00000X | 4930 | TN |
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 (MA); Practitioner - Physician Assistant (MS); Practitioner - Physician Assistant (TN) |
|---|
Part D prescriptions in 2024
| Prescriptions (claims) | 223 · 256 30-day fills |
|---|---|
| Patients | 181 |
| Total drug cost | $30,850 |
| Generic share | 71% of claims |
Education and affiliations
| Medical school | University of Tennessee, Hsc, College of Medicine |
|---|---|
| Graduation year | 2021 |
| Medicare specialty | Physician Assistant |
| Telehealth | Offers telehealth |
Medical group
- Pratt Medical Group IncBoston, MA · 286 clinicians
Hospital affiliations
- Cambridge Health AllianceCambridge, MA
- Tufts Medical CenterBoston, MA
Industry payments (Open Payments)
- 2025$714.92 · 7 payments from 2 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Janssen Biotech, Inc. | $452.66 | 5 |
| Madrigal Pharmaceuticals | $262.26 | 2 |
What the 2025 payments were for
- Food and Beverage$714.92 · 7 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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