Quick answers
- Does Nason Azizi accept Medicare assignment?
- Yes. Medicare's clinician data says Nason Azizi accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does Nason Azizi see?
- In 2024, CMS data shows 336 Original Medicare patients and 906 services for Nason Azizi. This counts Original Medicare only and measures volume, not quality.
- What is Nason Azizi's NPI number?
- 1538594973. 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 Nason Azizi, 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 | 336 |
|---|---|
| Services billed to Medicare | 906 |
| Different services or procedures | 9 |
| Participating Medicare provider | Yes |
| Average age of these patients | 77 |
Most frequent services
- Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes (99232)495 services
- Hospital discharge day management, 30 minutes or less (99238)127 services
- Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes (99233)93 services
- Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes (99231)70 services
- Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes (99222)53 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%
- Arthritis55%
- Chronic kidney disease46%
- Anxiety40%
- Heart failure40%
Hospitals where Nason Azizi works
Medicare's Facility Affiliation Data lists Nason Azizi at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- John Muir Medical Center - Concord CampusConcord, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050496
- John Muir Medical Center - Walnut Creek CampusWalnut Creek, CA · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 050180
- Providence Queen of the Valley Medical CenterNapa, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050009
Practice locations
Addresses where Nason Azizi is enrolled with Medicare (CMS data updated October 2, 2026).
- 2100 Napa Vallejo HwyNapa, CA 94558 (916) 651‑8811
- 2700 Grant St, Suite 200Concord, CA 94520 (925) 674‑0500
Group practices
Medicare enrollment lists Nason Azizi as a member of these groups (CMS data updated October 2, 2026).
- John Muir Physician Network494 clinicians in the group
- Department of State Hospitals270 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Napa
Clinicians with the same Medicare primary specialty in Napa, CA — not a recommendation.
Other clinicians in John Muir Physician Network
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2013 (13 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1538594973 |
| 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
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- 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