William P. Klein, MD
Internal Medicine Physician · Newport Beach, CA
William P. Klein, MD is an internal medicine physician with a practice address in Newport Beach, California, and NPI 1205834819, issued on Jul 8, 2005. Check the license (California G14712, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- William P. Klein
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- G14712 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1501 Superior Ave, Newport Beach, CA 92663
- Phone
- (949) 274-8030
- Enumerated
- Jul 8, 2005
- Record last updated
- Jan 17, 2008 (not updated in 18 years: call before relying on the address or phone)
- Fax
- (949) 642-3127
- Medicaid ID
- 00G147120 CA
- Medicare enrollment
- Enrolled (PECOS I20040721001089); accepts Medicare assignment
- Medical or professional school
- State University Of New York Downstate Medical Center, 1966
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 1501 Superior Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify William P. Klein in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G14712Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
86% more Medicare Part D claims than the average internal medicine physician in 2024
5,915 Medicare Part D claims for 455 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. 48 claims were for opioids.
Most prescribed
- Atorvastatin Calcium283 claims
- Levothyroxine Sodium278 claims
- Trelegy Ellipta250 claims
- Amlodipine Besylate211 claims
- Rosuvastatin Calcium194 claims
- Tamsulosin Hcl180 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
The MIPS final score for 2023 (Medicare payment program): 100 of 100
The Merit-based Incentive Payment System score is reported for this clinician. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $2,070.76
99 payments; by number, the most common kind was food and beverage; the largest payer was GlaxoSmithKline, LLC. The 50,334 providers of this specialty with any payment received $1,303.06 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- Huntington Beach Internal Medicine Group IncNewport Beach, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
William P. Klein among 17,696 internal medicine physician records in California
William P. Klein, MD is one of 17,696 internal medicine physician records with a practice address in California. 79% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 95% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated1966 · median 2004 among the 11,065 with a school on file
- Record last updated2008 · 61% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
94 internal medicine physician records list a practice address in Newport Beach
They are 94 of the 4,414 NPPES records with a practice address in Newport Beach, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Newport Beach → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- David Brouwer, MDNewport Beach, CA 926631629018544
- William Bruce, MDNewport Beach, CA 926631265490890
- Gary Carlson, MDNewport Beach, CA 926631497700116
- David Chun, MDNewport Beach, CA 926631730152976
- Dennis Jordanides, M.D.Newport Beach, CA 926631285638031
- Kambiz Karimi, MDNewport Beach, CA 926631720061823
- Gregory Katz, MDNewport Beach, CA 926631184674178
- Cameron Khavarian, M.D.Newport Beach, CA 926631104871938
Common questions
What is William P. Klein, MD's NPI number?
William P. Klein, MD's National Provider Identifier (NPI) is 1205834819, issued on Jul 8, 2005. An NPI identifies a provider in billing; it is not a license.
Where is William P. Klein, MD located?
The NPPES record lists a practice address at 1501 Superior Ave, Newport Beach, CA, 92663. Phone: (949) 274-8030. Providers update this record themselves, so call before visiting.
How can I verify William P. Klein, MD's license?
NPPES lists California license number G14712, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does William P. Klein, MD prescribe under Medicare Part D?
In 2024, William P. Klein, MD had 5,915 Medicare Part D claims for 455 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
What is William P. Klein, MD's MIPS final score?
The 2023 MIPS final score is 100 of 100. The average among 454,083 clinicians with a measured score was 83.5.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.