Gemma Tok Hyon Ko, M.D.
Internal Medicine Physician · Pico Rivera, CA
Gemma Tok Hyon Ko, M.D. is an internal medicine physician with a practice address in Pico Rivera, California, and NPI 1437167715, issued on Aug 3, 2006. Check the license (California G70866, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Gemma Tok Hyon Ko
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- G70866 CA
Self-reported in NPPES; status is on the state search - Practice location
- 4511 Rosemead Blvd, Pico Rivera, CA 90660
- Phone
- (562) 692-3388
- Enumerated
- Aug 3, 2006
- Record last updated
- Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
- Medicaid ID
- 00G708660 CA
- Medicare enrollment
- Enrolled (PECOS I20070108000566); accepts Medicare assignment
- Medical or professional school
- University Of Hawaii John A. Burns School Of Medicine, 1990
- 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 4511 Rosemead Blvd
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Parveen Ahmed, M.D.Internal Medicine Physician1669480745
- Khalid Nur, M.D.Internal Medicine Physician1235147521
- Daniel Woo, M.D.General Practice Physician1669670832
Verify Gemma Tok Hyon Ko in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G70866Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
13% more Medicare Part D claims than the average internal medicine physician in 2024
3,591 Medicare Part D claims for 145 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 10% of claims. 154 claims were for opioids.
Most prescribed
- Atorvastatin Calcium222 claims
- Losartan Potassium152 claims
- Hydrocodone-Acetaminophen107 claims
- Gabapentin101 claims
- Metformin Hcl92 claims
- Simvastatin84 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: $111.81
5 payments; by number, the most common kind was food and beverage; the largest payer was Novo Nordisk Inc. The 50,334 providers of this specialty with any payment received $1,303.06 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
- Gemma TH Ko,md. Inc.Pico Rivera, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Gemma Tok Hyon Ko among 17,696 internal medicine physician records in California
Gemma Tok Hyon Ko, 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 2006, is newer than 5% of them.
- NPI issued2006 · 5% of these records are older, 56% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated1990 · median 2004 among the 11,065 with a school on file
- Record last updated2007 · 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).
6 internal medicine physician records list a practice address in Pico Rivera
They are 6 of the 470 NPPES records with a practice address in Pico Rivera, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Pico Rivera → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Parveen Ahmed, M.D.Pico Rivera, CA 906601669480745
- David Ding, MDPico Rivera, CA 906601144583758
- Lam Nguyen, M.D.Pico Rivera, CA 906601538594122
- Khalid Nur, M.D.Pico Rivera, CA 906601235147521
- Dagmara Olsen, MDPico Rivera, CA 906601356912059
- Alast AhmadiNorwalk, CA 906501962088799
- Dane Copeland, M.D.Santa Fe Springs, CA 906701356409726
- Jennifer Cruz, NPNorwalk, CA 906501689309130
Common questions
What is Gemma Tok Hyon Ko, M.D.'s NPI number?
Gemma Tok Hyon Ko, M.D.'s National Provider Identifier (NPI) is 1437167715, issued on Aug 3, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Gemma Tok Hyon Ko, M.D. located?
The NPPES record lists a practice address at 4511 Rosemead Blvd, Pico Rivera, CA, 90660. Phone: (562) 692-3388. Providers update this record themselves, so call before visiting.
How can I verify Gemma Tok Hyon Ko, M.D.'s license?
NPPES lists California license number G70866, 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 Gemma Tok Hyon Ko, M.D. prescribe under Medicare Part D?
In 2024, Gemma Tok Hyon Ko, M.D. had 3,591 Medicare Part D claims for 145 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.