Philip Marjon, M.D.
NPI 1912234121 · Hematology & Oncology Physician · San Marcos, CA
Enrolled with Medicare as Practitioner - Hematology/Oncology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Philip Marjon, M.D. is a Hematology & Oncology Physician provider in San Marcos, CA (NPI 1912234121).
Provider details
- NPI number
- 1912234121
- Entity type
- Individual
- Primary specialty
- Hematology & Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- C175032 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
16 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
4 documented practice locations
- Medicare service volume (vs. specialty peers)25% of score
2,434 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
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 .
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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 391 | $136 |
| Complete Blood Cell Count (red Cells, White Blood Cell, Platelets), Automated Test and Automated Differential White Blood Cell Count85025 | 278 | $8 |
| Insertion of Needle Into Vein for Collection of Blood Sample36415 | 260 | $9 |
| Injection of Drug Or Substance Under Skin Or Into Muscle96372 | 250 | $16 |
| Infusion Into a Vein for Therapy, Prevention, Or Diagnosis, Additional Sequential Infusion, 1 Hour Or Less96367 | 190 | $32 |
| Administration of Chemotherapy Into Vein, 1 Hour Or Less96413 | 183 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 12 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Letrozole | 111 | 45 |
| Hydroxyurea | 46 | 19 |
| Zanubrutinibbrand: Brukinsa | 17 | — |
| Ondansetronbrand: Ondansetron Odt | 17 | — |
| Prednisone | 17 | 13 |
| Eltrombopag Olaminebrand: Promacta | 17 | — |
| Anastrozole | 14 | — |
| Famotidine |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$6,240 across 227 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Additional practice locations (3)
- 450 4th Ave Ste 311Chula Vista, CA 91910-4429Phone: (619) 371-9156
- 28078 Baxter Rd Ste 140Murrieta, CA 92563-1403Phone: (760) 733-9191
- 3965 5th Ave Ste 230San Diego, CA 92103-3107Phone: (619) 872-0953Fax: (619) 378-3162
Registry dates
- Enumerated
- 2009-11-09
- Last updated
- 2025-12-22
- Certified
- 2025-12-22
Frequently asked questions
- What is Philip Marjon's NPI number?
- Philip Marjon's National Provider Identifier (NPI) is 1912234121, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Philip Marjon's specialty?
- Philip Marjon is listed in the NPPES registry with a primary specialty of Hematology & Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is Philip Marjon located?
- Philip Marjon's practice location on file with NPPES is 838 Nordahl Rd Ste 300, San Marcos, CA 92069-3599.
- What is Philip Marjon's phone number?
- The practice phone number listed in the NPPES registry for Philip Marjon is (760) 747-8935.
- Does Philip Marjon accept Medicare?
- Philip Marjon is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Philip Marjon's NPI active?
- Yes — Philip Marjon's NPI (1912234121) is active in the NPPES registry as of the last update on 2025-12-22.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.