Katherine Danielle Williamson, MD
Pediatrics Physician · Lake Forest, CA
Katherine Danielle Williamson, MD is a pediatrics physician with a practice address in Lake Forest, California, and NPI 1982916375, issued on Jul 14, 2010. Check the license (California A112985, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Katherine Danielle Williamson
- Credential
- MD
- Primary taxonomy
- Pediatrics Physician 208000000X
- License number
- A112985 CA
Self-reported in NPPES; status is on the state search - Practice location
- 23321 EL Toro RD, Lake Forest, CA 92630
- Phone
- (949) 388-1798
- Enumerated
- Jul 14, 2010
- Record last updated
- Jan 17, 2017 (not updated in 9 years: call before relying on the address or phone)
- Entity
- Type 1 · individual
8 nearest pediatrics physician records → All 9,272 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.
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- Regina Brown, M.D.Pediatrics Physician1891892204
- Terence Chu, M.D.Pediatrics Physician1801991864
- Jennifer Eli, D.M.D.General Practice Dentistry1205103652
- William Gregg, DDSDentist1568589729
- Judith Leonard, PNP, BCPediatric Nurse Practitioner1639186067
Verify Katherine Danielle Williamson in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A112985Check 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: $482.03
21 payments; by number, the most common kind was food and beverage; the largest payer was Ironshore Pharmaceuticals Inc. The 21,580 providers of this specialty with any payment received $842.05 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.
Katherine Danielle Williamson among 9,272 pediatrics physician records in California
Katherine Danielle Williamson, MD is one of 9,272 pediatrics physician records with a practice address in California. 31% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2010, is newer than 63% of them.
- NPI issued2010 · 63% of these records are older, 34% newer
- In a Medicare fileYes · 31% of these records are
- In the CMS Doctors and Clinicians fileNo · 8% of these records are
- Record last updated2017 · 65% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 208000000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Pediatrics Physician providers in California
There are 9,272 pediatrics physician records in California.
All 9,272 in California → Every provider in Lake Forest → Pediatrics Physician nationwide →
The 8 pediatrics physician records with the nearest ZIP codes
- Eric Ball, M.D.Lake Forest, CA 926301316032972
- Regina Brown, M.D.Lake Forest, CA 926301891892204
- Terence Chu, M.D.Lake Forest, CA 926301801991864
- James Kay, D.O.Lake Forest, CA 926301962616656
- James Su, MDLake Forest, CA 926301457980278
- Roman Misiow, M.D.Dana Point, CA 926291205999000
- Iman Bar, MDCosta Mesa, CA 926271326127804
- Eugene Chen, MDCosta Mesa, CA 926271417933243
Common questions
What is Katherine Danielle Williamson, MD's NPI number?
Katherine Danielle Williamson, MD's National Provider Identifier (NPI) is 1982916375, issued on Jul 14, 2010. An NPI identifies a provider in billing; it is not a license.
Where is Katherine Danielle Williamson, MD located?
The NPPES record lists a practice address at 23321 EL Toro RD, Lake Forest, CA, 92630. Phone: (949) 388-1798. Providers update this record themselves, so call before visiting.
How can I verify Katherine Danielle Williamson, MD's license?
NPPES lists California license number A112985, 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.