Mark Janzen, MD
NPI 1932329265 · Vascular Surgery Physician · Riverside, CA
Enrolled with Medicare as Practitioner - Vascular Surgery · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Janzen, MD is a Vascular Surgery Physician provider in Riverside, CA (NPI 1932329265).
Provider details
- NPI number
- 1932329265
- Entity type
- Individual
- Primary specialty
- Vascular Surgery PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- Yes
- License
- 089484 (OH)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
1,243 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 | 568 | $96 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 101 | $65 |
| Ultrasonic Guidance for Blood Vessel Access76937 | 85 | $13 |
| Use of a Drug to Induce Depression of Consciousness By Physician Performing a Procedure (5 Years Or Older), Initial 15 Minutes99152 | 67 | $12 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 47 | $170 |
| Initial Hospital Care With Straightforward Or Low-Level Medical Decision Making, If Using Time, at Least 55 Minutes |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 3 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Hydrocodone/Acetaminophenbrand: Hydrocodone-Acetaminophen | 66 | 55 |
| Clopidogrel Bisulfatebrand: Clopidogrel | 57 | 37 |
| Cilostazol | 41 | 12 |
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.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$9,951 across 20 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
Registry dates
- Enumerated
- 2007-04-27
- Last updated
- 2017-01-27
Frequently asked questions
- What is Mark Janzen's NPI number?
- Mark Janzen's National Provider Identifier (NPI) is 1932329265, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Janzen's specialty?
- Mark Janzen is listed in the NPPES registry with a primary specialty of Vascular Surgery Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Janzen located?
- Mark Janzen's practice location on file with NPPES is 10800 Magnolia Avenue,, Riverside, CA 92505.
- What is Mark Janzen's phone number?
- The practice phone number listed in the NPPES registry for Mark Janzen is (440) 781-0931.
- Does Mark Janzen accept Medicare?
- Mark Janzen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mark Janzen's NPI active?
- Yes — Mark Janzen's NPI (1932329265) is active in the NPPES registry as of the last update on 2017-01-27.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.