Quick answers
- Does John D. Mastrovich accept Medicare assignment?
- Medicare's clinician data says John D. Mastrovich may accept Medicare assignment (as of October 2, 2026). Ask the office whether they accept it for your visit.
- How many Medicare patients does John D. Mastrovich see?
- In 2024, CMS data shows 59 Original Medicare patients and 1,069 services for John D. Mastrovich. This counts Original Medicare only and measures volume, not quality.
- What is John D. Mastrovich's NPI number?
- 1740205418. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for John D. Mastrovich, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 59 |
|---|---|
| Services billed to Medicare | 1,069 |
| Different services or procedures | 12 |
| Participating Medicare provider | Yes |
| Average age of these patients | 73 |
Most frequent services
- Professional service for preparation and provision of 1 or more antigens (95165)517 services
- Professional service for multiple injections of allergen (95117)176 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)71 services
- Test to measure rate of airflow (94375)26 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High blood pressure75%
- High cholesterol75%
- Arthritis59%
- Asthma53%
- Ischemic heart disease29%
- Depression29%
Practice locations
Addresses where John D. Mastrovich is enrolled with Medicare (CMS data updated October 2, 2026).
- 20650 Stone Oak Pkwy, Suite 106San Antonio, TX 78258 (210) 342‑6200
Specialties
- Allergy/Immunologyprimary
Other allergist and immunologists in San Antonio
Clinicians with the same Medicare primary specialty in San Antonio, TX — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Texas Tech University Health Science Center School Of Medicine |
| Graduation year | 1996 (30 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1740205418 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians