William Ezial Berger, M.D.
Allergy Physician · Mission Viejo, CA
William Ezial Berger, M.D. is an allergy physician with a practice address in Mission Viejo, California, and NPI 1538260583, issued on Sep 25, 2006. Check the license (California C35918, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- William Ezial Berger
- Credential
- M.D.
- Primary taxonomy
- Allergy Physician 207KA0200X
- License number
- C35918 CA
Self-reported in NPPES; status is on the state search - Practice location
- 27800 Medical Center RD, Mission Viejo, CA 92691
- Phone
- (949) 364-2900
- Enumerated
- Sep 25, 2006
- Record last updated
- Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
- Fax
- (949) 365-0117
- Entity
- Type 1 · individual
8 nearest allergy physician records → All 157 in California → Look up another NPI →
Also registered at 27800 Medical Center RD
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Stephen Ehrlich, M.D.Cardiovascular Disease Physician1700862547
Verify William Ezial Berger in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license C35918Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Industry payments in 2024: $101.64
1 payment: food and beverage; the largest payer was Genentech USA, Inc. The 502 providers of this specialty with any payment received $9,080.33 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.
William Ezial Berger among 157 allergy physician records in California
William Ezial Berger, M.D. is one of 157 allergy physician records with a practice address in California. 69% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 9% of them.
- NPI issued2006 · 9% of these records are older, 31% newer
- In a Medicare fileYes · 69% of these records are
- In the CMS Doctors and Clinicians fileNo · 52% of these records are
- Record last updated2007 · 70% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207KA0200X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Allergy Physician providers in California
There are 157 allergy physician records in California.
All 157 in California → Every provider in Mission Viejo → Allergy Physician nationwide →
The 8 allergy physician records with the nearest ZIP codes
- Geeta Venkat, M.D.Mission Viejo, CA 926911588774954
- Warner Carr, MDLaguna Niguel, CA 926771184798001
- Christine Lee-Kim, D.O.Laguna Niguel, CA 926771174881346
- Mark Sugar, M.D.Laguna Niguel, CA 926771013959253
- Bruce Friedman, MDFountain Valley, CA 927081457345225
- Gillian Bassirpour, MDAliso Viejo, CA 926561811216765
- Rhonda Myers, M.D.Irvine, CA 926041467404038
- Chittur Easwaran, M.DAnaheim, CA 928041750314993
Common questions
What is William Ezial Berger, M.D.'s NPI number?
William Ezial Berger, M.D.'s National Provider Identifier (NPI) is 1538260583, issued on Sep 25, 2006. An NPI identifies a provider in billing; it is not a license.
Where is William Ezial Berger, M.D. located?
The NPPES record lists a practice address at 27800 Medical Center RD, Mission Viejo, CA, 92691. Phone: (949) 364-2900. Providers update this record themselves, so call before visiting.
How can I verify William Ezial Berger, M.D.'s license?
NPPES lists California license number C35918, 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.
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.