Tat S. Lam, MD
Family Medicine Physician · Orange, CA
Tat S. Lam, MD is a family medicine physician with a practice address in Orange, California, and NPI 1134288749, issued on Dec 8, 2006. Check the license (California A62418, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Tat S. Lam
- Credential
- MD
- Primary taxonomy
- Family Medicine Physician 207Q00000X
- License number
- A62418 CA
Self-reported in NPPES; status is on the state search - Practice location
- 2501 E Chapman Ave Ste 204, Orange, CA 92869
- Phone
- (714) 628-3230
- Enumerated
- Dec 8, 2006
- Record last updated
- Apr 1, 2022
- Medicare enrollment
- Enrolled (PECOS I20101129000908); accepts Medicare assignment
- Medical or professional school
- University Of Southern California Keck School Of Medicine, 1995
- Entity
- Type 1 · individual
Also registered at 2501 E Chapman Ave Ste 204
A shared address usually means a shared clinic or building; it does not show who employs whom.
- June Makiyama, PA-CPhysician Assistant1508063827
- Kate Monahan, DOInternal Medicine Physician1043848732
Verify Tat S. Lam in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A62418Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
77% fewer Medicare Part D claims than the average family medicine physician in 2024
827 Medicare Part D claims for 491 beneficiaries, against an average of 3,544 among the 117,163 providers of this specialty who prescribed in Part D. Brand-name drugs were 9% of claims. 30 claims were for opioids.
Most prescribed
- Ipratropium Bromide167 claims
- Cefuroxime123 claims
- Doxycycline Hyclate58 claims
- Cefdinir51 claims
- Lidocaine46 claims
- Mupirocin45 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
- Providence Medical FoundationFullerton, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
106 family medicine physician records list a practice address in Orange
They are 106 of the 13,245 NPPES records with a practice address in Orange, and 17,133 family medicine physician records in California.
All 106 in Orange → All 17,133 in California → Every provider in Orange →
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- Vanessa Abarca, DOVentura, CA1952040859
- Lorraine Abate, M.D.Sacramento, CA1104840008
- Robert Abatecola, MDCastro Valley, CA1669551719
- Romeo Abaya, M.D.Cottonwood, CA1598053506
- Effiem Abbah, MD, MPHSan Francisco, CA1821185133
- Khuzeman Abbasi, MDSanta Rosa, CA1841979952
Common questions
What is Tat S. Lam, MD's NPI number?
Tat S. Lam, MD's National Provider Identifier (NPI) is 1134288749, issued on Dec 8, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Tat S. Lam, MD located?
The NPPES record lists a practice address at 2501 E Chapman Ave Ste 204, Orange, CA, 92869. Phone: (714) 628-3230. Providers update this record themselves, so call before visiting.
How can I verify Tat S. Lam, MD's license?
NPPES lists California license number A62418, 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 Tat S. Lam, MD prescribe under Medicare Part D?
In 2024, Tat S. Lam, MD had 827 Medicare Part D claims for 491 beneficiaries; the average among family medicine physician prescribers was 3,544. 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.