Gemma Tok Hyon Ko, M.D.

Internal Medicine

Gemma Tok Hyon Ko is an Internal Medicine specialist based in Pico Rivera, CA with over 36 years of clinical experience. Offers virtual telehealth visits.

(562) 692-3388Pico Rivera, CA
Telehealth Available
NPI Active per CMS — Q2 2026

Gemma Tok Hyon Ko, M.D. has been part of the Pico Rivera medical community since 2006 in group practice. A University of Hawaii John a. Burns School of Medicine graduate since 1990, she brings 36+ years of experience. CMS Medicare data shows her patients commonly have hypertension, high cholesterol, and diabetes.

At a glance

  • Uses generic medications more than 58% of reporting doctors in California
  • Virtual visits available — no app or travel required
1 of 3,565 Internal Medicine providers in CASee all Internal Medicine in Pico Rivera36+ years experienceNPI since 2006

Older · 6894dNPPES updated 2007-07-08 · verify NPI on CMS · Verify license at Medical Board of California

Contact & Location

Practice Location

4511 Rosemead Blvd, Pico Rivera, CA 90660-2032

Patient Condition Panel

What This Doctor Treats Most

Based on Medicare claims data — here's what patients commonly see this doctor for

Based on Medicare data, this doctor primarily manages Hypertension, High Cholesterol, and Diabetes.

Hypertension
Higher than avg (+5%)75%

High blood pressure — a leading risk factor for heart disease and stroke

US avg: 70.2%

↑ More patients than average (+5%) — a focus area for this doctor

High Cholesterol
Higher than avg (+5%)75%

Elevated cholesterol or triglycerides that increase heart disease risk

US avg: 70.4%

↑ More patients than average (+5%) — a focus area for this doctor

Diabetes
Higher than avg (+17%)51%

A condition where the body cannot properly regulate blood sugar levels

US avg: 34.5%

↑ More patients than average (+17%) — a focus area for this doctor

Arthritis
Lower than avg (-2%)47%

Joint inflammation causing pain, swelling, and stiffness

US avg: 49.3%

↓ Fewer patients than average (-2%) — less common here

Chronic Kidney Disease
Higher than avg (+14%)44%

Gradual loss of kidney function over time, often linked to diabetes or hypertension

US avg: 29.6%

↑ More patients than average (+14%) — a focus area for this doctor

Depression
Higher than avg (+6%)38%

A mood disorder causing persistent sadness and loss of interest in activities

US avg: 31.8%

↑ More patients than average (+6%) — a focus area for this doctor

Mood Disorders
38%

Conditions affecting emotional state, including depression and bipolar disorder

Anxiety Disorders
Lower than avg (-1%)33%

Excessive worry or fear that interferes with daily life

US avg: 34.1%

↓ Fewer patients than average (-1%) — less common here

GeneralBehavioralNational avg

Percentage of this provider's Medicare patients diagnosed with each condition. Source: CMS Utilization Data.

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Background & Specialty

Education, training, and specialty classification from CMS NPPES and Medicare records.

Career Journey
  1. Graduated medical school · 1990

    University of Hawaii John a. Burns School of Medicine

  2. 36 years in practice

    Senior practitioner

Internal MedicineAllopathic & Osteopathic Physicians

A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.

Taxonomy: 207R00000X

Education & Training

University of Hawaii John a. Burns School of Medicine (Class of 1990)

Practice Footprint

Mailing address

Po Box 1699, Whittier, CA 90609-1699

Differs from practice location

Virtual Internal Medicine Care With Gemma Tok Hyon Ko

NPPES records indicate this provider offers telehealth services. Contact the office to confirm availability and scheduling.

Schedule a virtual visit with Gemma Tok Hyon Ko for blood pressure monitoring, cholesterol management, diabetes check-ins — no travel to Pico Rivera required. The office sends a secure video link before your appointment. Most visits take 15–30 minutes.

Frequently Asked Questions

Common questions about Gemma Tok Hyon Ko

Dr. Ko is listed as active in the NPI registry with telehealth listed in Pico Rivera, CA. NPI status alone doesn't confirm open availability — call the office to confirm. Phone: (562) 692-3388.

Verified across 4 federal data sources

Sourced from CMS NPPES · OIG LEIE · CMS Medicare Part D · CMS Physician Comparator. See Data Methodology.

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Medical Disclaimer: NPI Telehealth is a provider directory for informational purposes only. This page does not constitute medical advice, diagnosis, or treatment recommendations. Provider data is sourced from the CMS NPPES federal registry and public Medicare datasets. NPI Telehealth does not verify clinical qualifications beyond federal records. Data may not reflect real-time availability — always contact the provider's office directly to confirm details before seeking care.

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