William Young Gregg, DDS
Dentist · Lake Forest, CA
William Young Gregg, DDS is a dentist with a practice address in Lake Forest, California, and NPI 1568589729, issued on Mar 23, 2007. Check the license (California 26644, as entered in NPPES) with the California board that licenses this profession; the federal record below is the public data PlainDoctor holds for this provider.
- Name
- William Young Gregg
- Credential
- DDS
- Primary taxonomy
- Dentist 122300000X
- License number
- 26644 CA
Self-reported in NPPES; status is on the state search - Practice location
- 23321 EL Toro RD, Lake Forest, CA 92630
- Phone
- (949) 770-7686
- Enumerated
- Mar 23, 2007
- Record last updated
- Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
- Fax
- (949) 770-0725
- Entity
- Type 1 · individual
8 nearest dentist records → All 14,729 in California → Look up another NPI →
Also registered at 23321 EL Toro RD
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Michael Bissiri, DDSGeneral Practice Dentistry1215250600
- Regina Brown, M.D.Pediatrics Physician1891892204
- Terence Chu, M.D.Pediatrics Physician1801991864
- Jennifer Eli, D.M.D.General Practice Dentistry1205103652
- Judith Leonard, PNP, BCPediatric Nurse Practitioner1639186067
- Anneke Sager, C.P.N.P.Pediatric Nurse Practitioner1245416239
Verify William Young Gregg in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license 26644Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
William Young Gregg among 14,729 dentist records in California
William Young Gregg, DDS is one of 14,729 dentist records with a practice address in California. 56% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does not. Its NPI, issued in 2007, is newer than 18% of them.
- NPI issued2007 · 18% of these records are older, 58% newer
- In a Medicare fileNo · 56% of these records are
- In the CMS Doctors and Clinicians fileNo · under 1% of these records are
- Record last updated2007 · 73% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 122300000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
32 dentist records list a practice address in Lake Forest
They are 32 of the 1,008 NPPES records with a practice address in Lake Forest, and 14,729 dentist records in California. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.
All 14,729 in California → Every provider in Lake Forest → Dentist nationwide →
The 8 dentist records with the nearest ZIP codes
- Shervin Ahmadnia, DDSLake Forest, CA 926301720120801
- Thomas Anderson, D.D.S.Lake Forest, CA 926301710152517
- Brent Bowling, D.D.S.Lake Forest, CA 926301609081611
- Anthony Follico, DDSLake Forest, CA 926301568565653
- Ha Lee, DDSLake Forest, CA 926301912153099
- Kathy Maasoumi, D.D.S.Lake Forest, CA 926301407998941
- Shidrokh Mafi, DDSLake Forest, CA 926301720295348
- Nazafarine Mahroo, DDSLake Forest, CA 926301639343775
Common questions
What is William Young Gregg, DDS's NPI number?
William Young Gregg, DDS's National Provider Identifier (NPI) is 1568589729, issued on Mar 23, 2007. An NPI identifies a provider in billing; it is not a license.
Where is William Young Gregg, DDS located?
The NPPES record lists a practice address at 23321 EL Toro RD, Lake Forest, CA, 92630. Phone: (949) 770-7686. Providers update this record themselves, so call before visiting.
How can I verify William Young Gregg, DDS's license?
NPPES lists California license number 26644, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. 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.