Dr. William K. Armstrong, MD
Family Medicine (Family Medicine Physician)
- Medicare participating
At a glance
- Years since graduation
- 19
- In the NPI registry since
- 2009
- Medicare patients seen, 2024
- 359
Licensed in California since 2009, according to the Medical Board of California. We show license dates only for the states that publish them in bulk; see which states do. For other states, check the state medical board.
The NPI date is when this clinician registered for a National Provider Identifier, the billing number used on health claims. It is not a license, graduation or board-certification date. What an NPI is
Education and training
- 2009Registered with an NPI (national billing number; not a license date)
Medicare’s Care Compare data doesn’t list this clinician’s medical school. Undergraduate school, residency, fellowship, licensing exams and board certification aren’t in public federal data. Board certification can be confirmed with the certifying board (ABMS member boards for MDs, AOA boards for DOs).
Specialties and state licenses
-
Family Medicine Physician primary
CA license A108913 (first issued 2009; current)
As reported to the NPI registry. To confirm a license is current, check the state medical board.
Where they work
Hospitals
- Uci Health-Orange Orange, CA
- Hoag Memorial Hospital Presbyterian Newport Beach, CA
Medical groups
- Hoag Clinic (460 clinicians)
Hospitals this clinician lists with Medicare, and groups they bill Medicare through (Care Compare). Affiliation doesn’t mean they see patients at every location.
Medicare patients and services
- Medicare patients, 2024
- 359
- Services billed
- 1,164
- Patients’ average age
- 74
| Service | Times | Patients |
|---|---|---|
| Established patient office or other outpatient visit, 30-39 minutes | 284 | 179 |
| Established patient office or other outpatient visit, 20-29 minutes | 120 | 91 |
| Administration of pneumococcal vaccine | 82 | 82 |
| Pneumococcal conjugate vaccine, 20 valent (pcv20), for intramuscular use | 82 | 82 |
| Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit | 50 | 50 |
| Electrocardiogram, routine ecg with 12 leads; interpretation and report only, performed as a screening for the initial preventive physical examination | 42 | 42 |
| Administration of influenza virus vaccine | 39 | 39 |
| Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report | 32 | 32 |
| Annual wellness visit; includes a personalized prevention plan of service (pps), initial visit | 30 | 30 |
| Influenza vaccine split virus, preservative free | 24 | 24 |
Medicare fee-for-service only. CMS leaves out services billed for fewer than 11 patients. These figures describe a practice’s Medicare work; they aren’t a measure of quality.
Medicare prescriptions
Prescriptions filled under Medicare Part D, including refills. CMS leaves out drugs prescribed fewer than 11 times.
Payments from drug and device companies
In 2025, 9 companies reported 16 payments worth $300 in total to this clinician.
| Lilly USA, LLC | $66.96 |
|---|---|
| Amgen Inc. | $66.68 |
| Pfizer Inc. | $39.39 |
| AbbVie Inc. | $25.28 |
| Sanofi-aventis U.S. LLC | $24.98 |
| Novo Nordisk Inc | $22.86 |
| Sumitomo Pharma America, Inc. | $22.75 |
| Esperion Therapeutics, Inc. | $17.60 |
| Food and Beverage | $300 |
|---|
From CMS Open Payments. A payment is not evidence of wrongdoing; many are for consulting, teaching or meals. Clinicians can review and dispute their records with CMS.