Physician Profile
Unclaimed ProfileAbout KO
Based in Pico Rivera, CA, Gemma Tok Hyon Ko, M.D. is listed in the NPI registry under internal medicine. Gemma graduated from University of Hawaii John A. Burns School of Medicine in 1990. Medicare claims data shows Gemma provided 764 services to 246 patients.
Summarised automatically from public NPI registry and CMS Medicare data. Not written or reviewed by this provider. Claim this profile to replace it.
Education & Training
Areas of Expertise
Licensing & Certification
Source: NPPES NPI Registry
Contact Information
- (562) 692-3388
- Email not available
Practice Locations
4511 ROSEMEAD BLVD
Pico Rivera, CA 90660
Procedures Most Often Billed to Medicare
764 services · 246 patients · 10 distinct codes
| Procedure | Type | Code | Services |
|---|---|---|---|
| Insertion of needle into vein for collection of blood sample | Procedure | 36415 |
113 |
| Collection and interpretation of physical parameters stored in computers and/or transmitted by the patient and/or caregiver to qualified health care professional, requiring 30 minutes or more, per 30 days | Treatment | 99091 |
57 |
| Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more | Office visit | 99214 |
223 |
| Visit complexity inherent to evaluation and management associated with medical care services that serve as the continuing focal point for all needed health care services and/or with medical care services that are part of ongoing care related to a patient' | Billing code | G2211 |
102 |
| Management using the results of remote vital sign monitoring per calendar month, first 20 minutes | Office visit | 99457 |
68 |
| Remote monitoring of physiologic parameters, initial supply of devices with daily recordings or programmed alerts transmission, each 30 days | Office visit | 99454 |
65 |
| Telephone medical discussion with physician, 21-30 minutes | Office visit | 99443 |
58 |
| Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit | Billing code | G0439 |
33 |
| Management using the results of remote vital sign monitoring per calendar month, each additional 20 minutes | Office visit | 99458 |
33 |
| Remote monitoring of physiologic parameters, initial set-up and patient education on use of equipment | Office visit | 99453 |
12 |
Source: CMS Medicare public data. Shows how often procedures were billed — not quality of care or patient satisfaction.
Related providers
Connections drawn from the registry and from what providers have told us. A link here is not a referral or an endorsement.
Other internal medicines at this location 2
Same specialty, same street address — most likely the same department or group.
Also at this address 4
Providers at the same street address. Each files their own registry entry, so a shared practice often appears under several different names.
Other internal medicines in Pico Rivera 5
Same specialty, same city.
More connections — 23 related providers in 3 groups
Trained at University of Hawaii John A. Burns School of Medicine 8
Other providers in the same specialty who trained at the same institution.
Class of 1990 at University of Hawaii John A. Burns School of Medicine 7
Providers who graduated from the same medical school in the same year.
Also performs Insertion of needle into vein for collection of blood sample 8
Providers in CA who bill this service to Medicare most often.
Common questions
What is Dr. Ko's specialty?
Dr. Ko is an internal medicine in Pico Rivera, CA. This is the primary taxonomy recorded against the NPI in the federal registry, listed there as “INTERNAL MEDICINE”.
NPI registry
Where can I find Dr. Ko?
Dr. Ko is listed at 4511 ROSEMEAD BLVD, Pico Rivera, CA 90660. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
How do I contact Dr. Ko?
The number on file is (562) 692-3388. Guide.md cannot book appointments or pass on messages — please call the office directly.
NPI registry
What is the NPI for Dr. Ko?
Dr. Ko's National Provider Identifier is 1437167715. It is issued by the Centers for Medicare & Medicaid Services and is unique and permanent — it does not change if they move practice.
NPI registry
What is Dr. Ko's medical education?
Dr. Ko attended University of Hawaii John A. Burns School of Medicine, graduating in 1990. This comes from the CMS National Downloadable File.
CMS public data
How much experience does Dr. Ko have?
Dr. Ko has 36 years experience. Calculated from a graduation year of 1990, reported in the CMS National Downloadable File.
CMS public data
What is Dr. Ko known for?
According to Medicare billing data, Dr. Ko performs procedures including insertion of needle into vein for collection of blood sample; provides treatments such as collection and interpretation of physical parameters stored in computers and/or transmitted by the patient and/or caregiver to qualified health care professional, requiring 30 minutes or more, per 30 days, alongside routine visits and testing. This reflects Medicare patients only and is billing volume, not a measure of quality.
Medicare claims
Is Dr. Ko's profile verified?
Not yet. This profile is built from public federal data and has not been confirmed by Dr. Ko. If this is you, claiming it is free.
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Claim this profileProvider data sourced from the NPPES NPI Registry and CMS public datasets. Information is provided for reference and is not medical advice.