Quick answers
- Does Hillary D. Brennan accept Medicare assignment?
- Yes. Medicare's clinician data says Hillary D. Brennan 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 Hillary D. Brennan see?
- In 2024, CMS data shows 175 Original Medicare patients and 189 services for Hillary D. Brennan. This counts Original Medicare only and measures volume, not quality.
- What is Hillary D. Brennan's NPI number?
- 1417243577. 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 Hillary D. Brennan, 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 | 175 |
|---|---|
| Services billed to Medicare | 189 |
| Different services or procedures | 33 |
| Participating Medicare provider | Yes |
| Average age of these patients | 74 |
Most frequent services
- Anesthesia for lens surgery (00142)39 services
- Anesthesia for other procedure on large bowel using an endoscope (00811)32 services
- Anesthesia for exam of colon using an endoscope (00812)13 services
- Anesthesia for other procedure on esophagus, stomach, or upper small bowel using an endoscope (00731)12 services
- Anesthesia for procedure on small and large bowel using an endoscope (00813)11 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 cholesterol75%
- High blood pressure71%
- Arthritis50%
- Diabetes29%
- Ischemic heart disease25%
- Chronic kidney disease23%
Hospitals where Hillary D. Brennan works
Medicare's Facility Affiliation Data lists Hillary D. Brennan 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.
- Adventist Health St HelenaSaint Helena, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050013
- 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 Hillary D. Brennan is enrolled with Medicare (CMS data updated October 2, 2026).
- 10 Woodland RdSaint Helena, CA 94574 (707) 963‑3611
- 1000 Trancas StNapa, CA 94558 (707) 252‑4411
- 1165 Montgomery DrSanta Rosa, CA 95405 (707) 546‑3210
- 1720 4th StSanta Rosa, CA 95404 (707) 546‑8100
- 4 Medical Plaza Dr, Suite 210Roseville, CA 95661 (916) 773‑8780
Group practices
Medicare enrollment lists Hillary D. Brennan as a member of these groups (CMS data updated October 2, 2026).
- St. Helena Hospital84 clinicians in the group
- Anesthesia and Analgesia Medical Group Inc73 clinicians in the group
- Mai Nursing Anesthesia PC35 clinicians in the group
- Green Anesthesia22 clinicians in the group
Specialties
Find other clinicians: Certified Registered Nurse Anesthetist (CRNA), California →
Other nurse anesthetists in Saint Helena
Clinicians with the same Medicare primary specialty in Saint Helena, CA — not a recommendation.
Other clinicians in St. Helena Hospital
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | CNA |
|---|---|
| Graduation year | 2011 |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1417243577 |
| 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