John Walker, M.D.
NPI 1477780344 · Vascular & Interventional Radiology Physician · San Antonio, TX
Enrolled with Medicare as Practitioner - Diagnostic Radiology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
John Walker, M.D. is a Vascular & Interventional Radiology Physician provider in San Antonio, TX (NPI 1477780344).
Provider details
- NPI number
- 1477780344
- Entity type
- Individual
- Primary specialty
- Vascular & Interventional Radiology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- P1944 (TX)
Specialties & taxonomies
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
17 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
366 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) |
|---|---|---|
| Use of a Drug to Induce Depression of Consciousness By Physician Performing a Procedure (5 Years Or Older), Initial 15 Minutes99152 | 103 | $12 |
| Review By Radiologist of Additional Artery Image75774 | 39 | $46 |
| Ultrasonic Guidance for Blood Vessel Access76937 | 39 | $14 |
| Ultrasonic Guidance for Needle Placement76942 | 32 | $29 |
| Fluoroscopic Guidance for Insertion Or Removal of Central Vein Access Device77001 | 25 | $18 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 25 | $97 |
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 |
|---|---|---|
| Hydrocodone/Acetaminophenbrand: Hydrocodone-Acetaminophen | 20 | 18 |
| Ondansetronbrand: Ondansetron Odt | 19 | 17 |
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.
$11,807 across 23 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
- 2009-06-17
- Last updated
- 2024-12-11
- Certified
- 2024-12-11
Frequently asked questions
- What is John Walker's NPI number?
- John Walker's National Provider Identifier (NPI) is 1477780344, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Walker's specialty?
- John Walker is listed in the NPPES registry with a primary specialty of Vascular & Interventional Radiology Physician (Allopathic & Osteopathic Physicians).
- Where is John Walker located?
- John Walker's practice location on file with NPPES is 4502 Medical Dr, San Antonio, TX 78229-4402.
- What is John Walker's phone number?
- The practice phone number listed in the NPPES registry for John Walker is (210) 358-4000.
- Does John Walker accept Medicare?
- John Walker is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is John Walker's NPI active?
- Yes — John Walker's NPI (1477780344) is active in the NPPES registry as of the last update on 2024-12-11.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.