Gregory Jason Lam, M.D.
Internal Medicine Physician · Laguna Hills, CA
Gregory Jason Lam, M.D. is an internal medicine physician with a practice address in Laguna Hills, California, and NPI 1871955922, issued on Mar 27, 2016. Check the license (California A151470, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Gregory Jason Lam
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A151470 CA
Self-reported in NPPES; status is on the state search - Practice location
- 23961 Calle DE LA Magdalena Ste 200, Laguna Hills, CA 92653
- Phone
- (949) 238-4100
- Enumerated
- Mar 27, 2016
- Record last updated
- Jul 18, 2024
- Medicare enrollment
- Enrolled (PECOS I20190819002705); accepts Medicare assignment
- Medical or professional school
- University Of California, San Francisco School Of Medicine, 2016
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 23961 Calle DE LA Magdalena Ste 200
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Charles Blumberg, MDInternal Medicine Physician1225532310
- Gol Golshani, M.DHematology & Oncology Physician1629497797
Verify Gregory Jason Lam in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A151470Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
89% fewer Medicare Part D claims than the average internal medicine physician in 2024
364 Medicare Part D claims for 172 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 6% of claims.
Most prescribed
- Atorvastatin Calcium34 claims
- Rosuvastatin Calcium21 claims
- Amlodipine Besylate20 claims
- Levothyroxine Sodium13 claims
- Tamsulosin Hcl13 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.
Bills Medicare through one group practice
- Regents OF The University OF CaliforniaOrange, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Gregory Jason Lam among 17,696 internal medicine physician records in California
Gregory Jason Lam, M.D. 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 2016, is newer than 79% of them.
- NPI issued2016 · 79% of these records are older, 19% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2016 · median 2004 among the 11,065 with a school on file
- Record last updated2024 · 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).
56 internal medicine physician records list a practice address in Laguna Hills
They are 56 of the 2,069 NPPES records with a practice address in Laguna Hills, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Laguna Hills → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Humberto Boccardo, M.D.Laguna Hills, CA 926531689679458
- Arthur Daigneault, MDLaguna Hills, CA 926531609845361
- Raymond Fernandez, MDLaguna Hills, CA 926531629039532
- Ali Ghazvini, M.D.Laguna Hills, CA 926531104865153
- Brian HenryLaguna Hills, CA 926531629047824
- Robert Lazatin, M.D.Laguna Hills, CA 926531700865755
- Alan Lo, MDLaguna Hills, CA 926531982683637
- Lawrence Luppi, M.D.Laguna Hills, CA 926531952356727
Common questions
What is Gregory Jason Lam, M.D.'s NPI number?
Gregory Jason Lam, M.D.'s National Provider Identifier (NPI) is 1871955922, issued on Mar 27, 2016. An NPI identifies a provider in billing; it is not a license.
Where is Gregory Jason Lam, M.D. located?
The NPPES record lists a practice address at 23961 Calle DE LA Magdalena Ste 200, Laguna Hills, CA, 92653. Phone: (949) 238-4100. Providers update this record themselves, so call before visiting.
How can I verify Gregory Jason Lam, M.D.'s license?
NPPES lists California license number A151470, 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 Gregory Jason Lam, M.D. prescribe under Medicare Part D?
In 2024, Gregory Jason Lam, M.D. had 364 Medicare Part D claims for 172 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions 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. 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.