Dr. William P. Klein, MD
Internal Medicine (Internal Medicine Physician)
- Medicare participating
At a glance
- Medical school
- State University of New York Downstate Medical Center (1966)
- Years since graduation
- 60
- In the NPI registry since
- 2005
- Medicare patients seen, 2024
- 350
Licensed in California since 1968, 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. NPIs were first issued in May 2005 and became required on claims in 2007–2008, so an early date usually means the clinician was already in practice before then. What an NPI is
Education and training
- 1966Medical school: State University of New York Downstate Medical Center
- 2005Registered with an NPI (national billing number; not a license date) — NPIs began in 2005, so practice likely started earlier
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
-
Internal Medicine Physician primary
CA license G14712 (first issued 1968; current)
As reported to the NPI registry. To confirm a license is current, check the state medical board.
Where they work
Hospitals
- Hoag Memorial Hospital Presbyterian Newport Beach, CA
- Memorialcare Saddleback Medical Center Laguna Hills, CA
- Memorialcare Orange Coast Medical Center Fountain Valley, CA
Medical groups
- Huntington Beach Internal Medicine Group Inc (3 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
- 350
- Services billed
- 1,522
- Patients’ average age
- 78
| Service | Times | Patients |
|---|---|---|
| Established patient office or other outpatient visit, 30-39 minutes | 777 | 257 |
| Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit | 227 | 227 |
| Established patient office or other outpatient visit, 40-54 minutes | 222 | 216 |
| Test to measure expiratory airflow and volume | 180 | 131 |
| Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report | 174 | 160 |
| New patient office or other outpatient visit, 45-59 minutes | 67 | 67 |
| Colorectal cancer screening; fecal occult blood test, immunoassay, 1-3 simultaneous | 54 | 54 |
| Transitional care management services for problem of high complexity | 25 | 21 |
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, 22 companies reported 99 payments worth $1,896 in total to this clinician.
| Genzyme Corporation | $352 |
|---|---|
| Insmed, Inc. | $250 |
| GlaxoSmithKline, LLC. | $239 |
| Ani Pharmaceuticals, Inc. | $147 |
| Amgen Inc. | $143 |
| Octapharma USA, Inc. | $121 |
| Lilly USA, LLC | $85.05 |
| Regeneron Healthcare Solutions, Inc. | $82.53 |
| Food and Beverage | $1,896 |
|---|
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.