Mark Buyyounouski, M.D.
NPI 1912927021 · Radiation Oncology Physician · Stanford, CA
Enrolled with Medicare as Practitioner - Radiation Oncology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Buyyounouski, M.D. is a Radiation Oncology Physician provider in Stanford, CA (NPI 1912927021).
Provider details
- NPI number
- 1912927021
- Entity type
- Individual
- Primary specialty
- Radiation Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- MD4211507 (PA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Other Service Providers
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
19 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
1,537 Medicare services, 2024 (ranked within specialty)
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 methodology.
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) |
|---|---|---|
| Ct Guidance for Insertion of Radiation Therapy Fields77014 | 565 | $52 |
| Calculation of Radiation Therapy Dose77300 | 220 | $38 |
| Radiation Treatment Management, 5 Treatment Sessions77427 | 139 | $222 |
| Complex Radiation Therapy Planning77263 | 83 | $192 |
| New Patient Office Or Other Outpatient Visit With a High Level of Medical Decision Making, If Using Time, 60 Minutes Or More99205 | 71 | $204 |
| 3d Radiation Therapy Planning77295 | 58 | $261 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 2 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Tamsulosin Hcl | 40 | 23 |
| Famotidine | 29 | 19 |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-07-20
- Last updated
- 2016-04-01
Frequently asked questions
- What is Mark Buyyounouski's NPI number?
- Mark Buyyounouski's National Provider Identifier (NPI) is 1912927021, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Buyyounouski's specialty?
- Mark Buyyounouski is listed in the NPPES registry with a primary specialty of Radiation Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Buyyounouski located?
- Mark Buyyounouski's practice location on file with NPPES is 300 Pasteur Dr, Stanford, CA 94305-2200.
- What is Mark Buyyounouski's phone number?
- The practice phone number listed in the NPPES registry for Mark Buyyounouski is (650) 723-4000.
- Does Mark Buyyounouski accept Medicare?
- Mark Buyyounouski is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mark Buyyounouski's NPI active?
- Yes — Mark Buyyounouski's NPI (1912927021) is active in the NPPES registry as of the last update on 2016-04-01.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.