Patrick Koo, MD
Gastroenterology Physician · Fullerton, CA
Patrick Koo, MD is a gastroenterology physician with a practice address in Fullerton, California, and NPI 1801152772, issued on Apr 5, 2012. Check the license (California A136521, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Patrick Koo
- Credential
- MD
- Primary taxonomy
- Gastroenterology Physician 207RG0100X
- License number
- A136521 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1837 Sunny Crest Dr, Fullerton, CA 92835
- Phone
- (714) 446-5831
- Enumerated
- Apr 5, 2012
- Record last updated
- Oct 22, 2024
- Fax
- (714) 446-7910
- Medicare enrollment
- Enrolled (PECOS I20180830001952); accepts Medicare assignment
- Medical or professional school
- Pennsylvania State University College Of Medicine, 2012
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest gastroenterology physician records → All 2,140 in California → Look up another NPI →
Also registered at 1837 Sunny Crest Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Martin Carr, M.D.Gastroenterology Physician1326034265
- Maica Javien, NP-CFamily Nurse Practitioner1255086443
- Thu Le, FNPFamily Nurse Practitioner1033698915
- Erica Lee, NPFamily Nurse Practitioner1013506740
- Sajen Mathews, MDGastroenterology Physician1326048323
- Jill Olmstead, N.P.Nurse Practitioner1740276732
Verify Patrick Koo in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A136521Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
54% more Medicare Part D claims than the average gastroenterology physician in 2024
1,246 Medicare Part D claims for 427 beneficiaries, against an average of 811 among the 16,445 providers of this specialty who prescribed in Part D. Brand-name drugs were 15% of claims.
Most prescribed
- Pantoprazole Sodium457 claims
- Colestipol Hcl68 claims
- Omeprazole49 claims
- Famotidine47 claims
- Linzess42 claims
- Dicyclomine Hcl36 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.
Industry payments in 2024: $1,683.96
101 payments; by number, the most common kind was food and beverage; the largest payer was Abbvie 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.
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).
Patrick Koo among 2,140 gastroenterology physician records in California
Patrick Koo, 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 2012, is newer than 77% of them.
- NPI issued2012 · 77% of these records are older, 20% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 72% of these records are
- Graduated2012 · median 2002 among the 1,538 with a school on file
- Record last updated2024 · 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 Fullerton → Gastroenterology Physician nationwide →
The 8 gastroenterology physician records with the nearest ZIP codes
- Martin Carr, M.D.Fullerton, CA 928351326034265
- Sajen Mathews, MDFullerton, CA 928351326048323
- Yeeshun Miao, M.D.Fullerton, CA 928351518953983
- Kumkum Patel, M.D., MPHFullerton, CA 928351003178138
- Vijay Prabhakar, M.D.Fullerton, CA 928351932593167
- Scott Sainburg, M.D.Fullerton, CA 928351184610552
- Eugene Yoon, M.D.Fullerton, CA 928351861618449
- Richard McGuire, M.D.Fullerton, CA 928321437196730
Common questions
What is Patrick Koo, MD's NPI number?
Patrick Koo, MD's National Provider Identifier (NPI) is 1801152772, issued on Apr 5, 2012. An NPI identifies a provider in billing; it is not a license.
Where is Patrick Koo, MD located?
The NPPES record lists a practice address at 1837 Sunny Crest Dr, Fullerton, CA, 92835. Phone: (714) 446-5831. Providers update this record themselves, so call before visiting.
How can I verify Patrick Koo, MD's license?
NPPES lists California license number A136521, 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 Patrick Koo, MD prescribe under Medicare Part D?
In 2024, Patrick Koo, MD had 1,246 Medicare Part D claims for 427 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.