Mathias A. Masem, M.D.
NPI 1508810938ActiveIndividual· Orthopaedic Surgery, Hand Surgery· Oakland, CA
Orthopaedic Surgery, Hand Surgery (M.D.) in Oakland, California, trained at University of Minnesota Medical School (class of 1975). 202 Medicare patients in 2024, $111,222 paid; nearly all of their 176 Part D prescriptions were generic (96%). Alafair Biosciences, Inc. was the largest of 5 companies reporting payments in 2025, $610.85 in all, mostly food and beverage.
Overview
| NPI | 1508810938 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | Yes |
| NPI issued | May 20, 2006 |
| Last updated in NPPES | Dec 18, 2014 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Orthopaedic Surgery, Hand Surgery Primary | 207XS0106X | G34134 | CA |
| Orthopaedic Surgery | 207X00000X | G34134 | CA |
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 - Orthopedic Surgery (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 202 |
|---|---|
| Services billed | 1,230 across 67 procedure codes |
| Paid by Medicare | $111,222 |
Part D prescriptions in 2024
| Prescriptions (claims) | 176 · 201 30-day fills |
|---|---|
| Patients | 72 |
| Total drug cost | $69,706 |
| Generic share | 96% of claims |
Education and affiliations
| Medical school | University of Minnesota Medical School |
|---|---|
| Graduation year | 1975 |
| Medicare specialty | Orthopedic Surgery |
| Telehealth | Offers telehealth |
Medical groups
- University of California San FranciscoSan Francisco, CA · 1,839 clinicians
- UCSF Medical Group Business ServicesSan Francisco, CA · 1,598 clinicians
- Mathias Masem MDOakland, CA · 2 clinicians
Hospital affiliations
- Alta Bates Summit Medical CenterOakland, CA
- Alta Bates Summit Medical Center - Alta Bates CampBerkeley, CA
- John Muir Medical Center - Walnut Creek CampusWalnut Creek, CA
- UCSF Medical CenterSan Francisco, CA
Industry payments (Open Payments)
- 2025$610.85 · 7 payments from 5 companies
- 2024$553.36 · 6 payments from 5 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Alafair Biosciences, Inc. | $196.53 | 1 |
| Axogen | $166.83 | 1 |
| Stryker Corporation | $125.35 | 1 |
| Endo USA, Inc. | $65.49 | 3 |
| Acumed LLC | $56.65 | 1 |
What the 2025 payments were for
- Food and Beverage$610.85 · 7 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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