Quick answers
- Does Caroline S. Onstott accept Medicare assignment?
- Yes. Medicare's clinician data says Caroline S. Onstott 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 Caroline S. Onstott see?
- In 2024, CMS data shows 61 Original Medicare patients and 119 services for Caroline S. Onstott. This counts Original Medicare only and measures volume, not quality.
- What is Caroline S. Onstott's NPI number?
- 1689635393. 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 Caroline S. Onstott, 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 | 61 |
|---|---|
| Services billed to Medicare | 119 |
| Different services or procedures | 19 |
| Participating Medicare provider | Yes |
| Average age of these patients | 76 |
Most frequent services
- Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes (99231)27 services
- Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes (99232)21 services
- Hospital discharge day management, 30 minutes or less (99238)13 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 pressure69%
- Arthritis61%
- Chronic kidney disease34%
- Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)33%
- Depression31%
Hospitals where Caroline S. Onstott works
Medicare's Facility Affiliation Data lists Caroline S. Onstott 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.
- Mayo Clinic HospitalPhoenix, AZ · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 030103
Practice locations
Addresses where Caroline S. Onstott is enrolled with Medicare (CMS data updated October 2, 2026).
- 13400 E Shea BlvdScottsdale, AZ 85259 (480) 301‑8000
- 5701 E Mayo BlvdPhoenix, AZ 85054 (480) 342‑4200
- 5777 E Mayo BlvdPhoenix, AZ 85054
- 5777 E Mayo Blvd, Mayo Clinic HospitalPhoenix, AZ 85054
- 5779 E Mayo Blvd, Speciality BuildingPhoenix, AZ 85054 (480) 301‑8000
Group practices
Medicare enrollment lists Caroline S. Onstott as a member of this group (CMS data updated October 2, 2026).
- Mayo Clinic Arizona1,626 clinicians in the group
Specialties
- Physician Assistantprimary
Other physician assistants in Scottsdale
Clinicians with the same Medicare primary specialty in Scottsdale, AZ — not a recommendation.
Other clinicians in Mayo Clinic Arizona
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | PA |
|---|---|
| Graduation year | 2004 |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1689635393 |
| 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