Daniel S. Seid, MD
Gastroenterology Physician · Fontana, CA
Daniel S. Seid, MD is a gastroenterology physician with a practice address in Fontana, California, and NPI 1053470658, issued on Dec 8, 2006. Check the license (California G65516, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Daniel S. Seid
- Credential
- MD
- Primary taxonomy
- Gastroenterology Physician 207RG0100X
- License number
- G65516 CA
Self-reported in NPPES; status is on the state search - Practice location
- 9961 Sierra Ave, Fontana, CA 92335
- Phone
- (909) 427-3910
- Enumerated
- Dec 8, 2006
- Record last updated
- Nov 30, 2021 (not updated in 5 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20081215000683); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest gastroenterology physician records → All 2,140 in California → Look up another NPI →
Also registered at 9961 Sierra Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Daniel S. Seid in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G65516Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
31% fewer Medicare Part D claims than the average gastroenterology physician in 2024
560 Medicare Part D claims for 288 beneficiaries, against an average of 811 among the 16,445 providers of this specialty who prescribed in Part D. Brand-name drugs were 11% of claims.
Most prescribed
- Gavilyte-C191 claims
- Mesalamine75 claims
- Colesevelam Hcl51 claims
- Omeprazole31 claims
- Ursodiol25 claims
- Zenpep17 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
- Southern California Permanente Medical GroupOntario, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Daniel S. Seid among 2,140 gastroenterology physician records in California
Daniel S. Seid, MD is one of 2,140 gastroenterology physician records with a practice address in California. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 7% of them.
- NPI issued2006 · 7% of these records are older, 48% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 72% of these records are
- Graduated1987 · median 2002 among the 1,538 with a school on file
- Record last updated2021 · 60% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RG0100X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Gastroenterology Physician providers in California
There are 2,140 gastroenterology physician records in California.
All 2,140 in California → Every provider in Fontana → Gastroenterology Physician nationwide →
The 8 gastroenterology physician records with the nearest ZIP codes
- Alexander Han, MDFontana, CA 923351790967743
- Patricia Hsia, MDFontana, CA 923351174694087
- Timothy Jenkins, MDFontana, CA 923351205903119
- David Kestenbaum, MDFontana, CA 923351285705236
- Eve Kirschner, MDFontana, CA 923351679640486
- Scott Marnoy, MDFontana, CA 923351104985779
- Timothy McCarter, MDFontana, CA 923351386628402
- Tommy Oei, MDFontana, CA 923351033286844
Common questions
What is Daniel S. Seid, MD's NPI number?
Daniel S. Seid, MD's National Provider Identifier (NPI) is 1053470658, issued on Dec 8, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Daniel S. Seid, MD located?
The NPPES record lists a practice address at 9961 Sierra Ave, Fontana, CA, 92335. Phone: (909) 427-3910. Providers update this record themselves, so call before visiting.
How can I verify Daniel S. Seid, MD's license?
NPPES lists California license number G65516, 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 Daniel S. Seid, MD prescribe under Medicare Part D?
In 2024, Daniel S. Seid, MD had 560 Medicare Part D claims for 288 beneficiaries; 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.