Marc H. Harwitt, M.D.
Gastroenterology Physician · Santa Monica, CA
Marc H. Harwitt, M.D. is a gastroenterology physician with a practice address in Santa Monica, California, and NPI 1285613943, issued on Jan 11, 2006. Check the license (California G23138, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Marc H. Harwitt
- Credential
- M.D.
- Primary taxonomy
- Gastroenterology Physician 207RG0100X
- License number
- G23138 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1301 20TH St Ste 280, Santa Monica, CA 90404
- Phone
- (310) 829-6789
- Enumerated
- Jan 11, 2006
- Record last updated
- Aug 28, 2020 (not updated in 6 years: call before relying on the address or phone)
- Fax
- (310) 935-3163
- Medicaid ID
- 00G231380 CA
- Entity
- Type 1 · individual
Also registered at 1301 20TH St Ste 280
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Julia Lee, PA-CPhysician Assistant1093280604
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Verify Marc H. Harwitt in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G23138Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
98% fewer Medicare Part D claims than the average gastroenterology physician in 2024
19 Medicare Part D claims, against an average of 811 among the 16,445 providers of this specialty who prescribed in Part D.
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.
Industry payments in 2024: $23.96
1 payment: food and beverage; the largest payer was Pfizer Inc. The 13,350 providers of this specialty with any payment received $5,015.95 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.
Gastroenterology Physician providers in California
There are 2,140 gastroenterology physician records in California.
Other gastroenterology physician records in California
- David Aarons, MDLodi, CA1619081379
- Constante Abaya, MDOxnard, CA1003918459
- Sadeea Abbasi, M.D., PH.D.Los Angeles, CA1366713513
- Basim Abdelkarim, MDUpland, CA1932217544
- Homan Abdollahzadeh, MDPalm Springs, CA1184634826
- John Abdulian, M.D.Fresno, CA1437114113
- Hussein Abidali, DORancho Cucamonga, CA1205274768
- Alaa Abousaif, MDOrange, CA1235124108
- Donald Abrahm, M.D.Newport Beach, CA1215022405
- Maria Abreu, M.D.West Hollywood, CA1598793374
Common questions
What is Marc H. Harwitt, M.D.'s NPI number?
Marc H. Harwitt, M.D.'s National Provider Identifier (NPI) is 1285613943, issued on Jan 11, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Marc H. Harwitt, M.D. located?
The NPPES record lists a practice address at 1301 20TH St Ste 280, Santa Monica, CA, 90404. Phone: (310) 829-6789. Providers update this record themselves, so call before visiting.
How can I verify Marc H. Harwitt, M.D.'s license?
NPPES lists California license number G23138, 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 Marc H. Harwitt, M.D. prescribe under Medicare Part D?
In 2024, Marc H. Harwitt, M.D. had 19 Medicare Part D claims; the average among gastroenterology physician prescribers was 811. 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.