WEI-FANG KO M.D.
NPI 1417068081
Internal Medicine - Gastroenterology in Castro Valley, CA

Q: What is Wei-fang Ko's NPI number?

The NPI number for Wei-fang Ko is 1417068081. It was assigned to this individual provider in the NPPES registry on August 31, 2006.

Q: What is Wei-fang Ko's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.

Q: When was this NPI record last updated?

The NPPES record for Wei-fang Ko was last updated on August 1, 2022. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.

Active since August 31, 2006PECOS EnrolledAccepts Medicare Assignment

80.9/100

CMS Quality Rating

19845 LAKE CHABOT RD, SUITE, 104, CASTRO VALLEY, CA 94546(510) 537-4415 Get Directions Write a Review

NPPES record last updated: August 1, 2022. Verified against the NPPES registry weekly; last sync: October 18, 2026.

On this page

About Wei-fang Ko M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

WEI-FANG KO M.D. (NPI 1417068081) is an individual gastroenterology provider in Castro Valley, California, licensed in California (A62022) and active in the NPI registry since August 2006. He is enrolled in Medicare PECOS and is a graduate of Other (1986).

NPPES Registry Identity

NPI1417068081

Entity TypeIndividualMale

Primary Taxonomy207RG0100X

Provider Legal NameWEI-FANG KOCredential: M.D.

Location Address19845 LAKE CHABOT RD, SUITE, 104Castro Valley, CA 94546-4055

Mailing Address19845 Lake Chabot Rd, Suite, 104Castro Valley, CA 94546-4055 · (510) 537-4415

Phone(510) 537-4415

Sole ProprietorNo

Medical School CMSOtherGraduated 1986

Enumeration DateAugust 31, 2006

Last NPPES UpdateAugust 1, 2022

NPPES CertifiedAugust 1, 2022

✔ NPI 1417068081 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · GastroenterologyAllopathic & Osteopathic Physicians

Taxonomy Code207RG0100X

License✔ Licensed in CA · A62022

Definition

An internist who specializes in diagnosis and treatment of diseases of the digestive organs including the stomach, bowels, liver and gallbladder. This specialist treats conditions such as abdominal pain, ulcers, diarrhea, cancer and jaundice and performs complex diagnostic and therapeutic procedures using endoscopes to visualize internal organs.

19845 LAKE CHABOT RD, Castro Valley, CA 94546

Open in Google Maps ↗

Other Identifiers 2

OtherZZZ25407ZCA · Service Locations With Zip 94545

OtherZZZ25408ZCA · Service Location Zipcode 94546 And 94541

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Wei-fang Ko M.d. is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID6406970995

PECOS Enrollment IDI20100907000347

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

Medicare enrollment records show Wei-fang Ko reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Gastroenterology Specialists Medical Group, Inc A Medical Corporation

Same address

Gastroenterology

19845 LAKE CHABOT RD, SUITE 104
Castro Valley, CA 94546

Reassigned Medicare billing, California enrollment
8 clinicians in this Medicare group

NPI 1629170998 (510) 537-4415

Genesis Healthcare Partners PC

420 mi

Specialist

320 SANTA FE DR STE 108
Encinitas, CA 92024

Reassigned Medicare billing, California enrollment
242 clinicians in this Medicare group

NPI 1548567498 (760) 436-4558

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims 14

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213

This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.

231 services154 patients

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 99232

Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.

121 services60 patients

New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more 99203

This service involves an initial office or outpatient visit for a new patient. The healthcare professional will spend 30-44 minutes understanding your health history, current issues, and discussing possible treatment plans. It's a comprehensive evaluation to start your healthcare journey.

113 services113 patients

New patient office or other outpatient visit with straightforward medical decision making, if using time, 15 minutes or more 99202

This service involves an initial visit to the doctor's office or other outpatient setting. It typically lasts between 15-29 minutes. The doctor will review your medical history, conduct a physical examination, and discuss your health concerns. It's a chance to establish your health baseline and address any immediate medical issues.

72 services72 patients

Removal of polyps or growths of large bowel using an endoscope with mechanical snare 45385

This procedure involves using a thin, flexible tube called an endoscope to examine the large bowel. If any abnormal growths or polyps are found, a tool called a mechanical snare is used to remove them. This is a common method to prevent potential health issues.

71 services71 patients

Biopsy of large bowel using a flexible endoscope 45380

A biopsy of the large bowel using a flexible endoscope is a procedure where a thin, flexible tube with a camera is inserted through the rectum to examine the bowel. If abnormal tissue is found, a small sample is taken for further examination. This helps in diagnosing conditions like inflammation, polyps, or cancer.

68 services68 patients

Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 99222

Initial hospital inpatient care is a service where a healthcare provider spends about 50 minutes per day overseeing your care while you're admitted in the hospital. This includes reviewing your health status, planning your treatment, and ensuring your safety and comfort.

45 services45 patients

Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 43239

This procedure involves using a thin, flexible tube with a light and camera, known as an endoscope, to examine the esophagus, stomach, and upper part of the small intestine. Small tissue samples are taken for further examination to help diagnose various conditions.

38 services37 patients

Established patient office or other outpatient visit with straightforward medical decision making, if using time, 10 minutes or more 99212

This is a routine check-up for patients who have previously seen the doctor. During this 10-19 minute visit, the doctor will review your health status, discuss any concerns, and manage ongoing treatments or medications. It's a chance to ensure your health is on track.

36 services35 patients

Colorectal cancer screening; colonoscopy on individual at high risk G0105

Colorectal cancer screening, specifically a colonoscopy, is a preventive measure for those at high risk. A thin, flexible tube with a camera inspects the colon to spot any abnormal growths. This test helps detect potential issues early, enhancing the effectiveness of treatment.

29 services29 patients

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 99233

Follow-up hospital inpatient care per day typically involves a 35-minute check-up by your healthcare provider. This service includes monitoring your health progress, adjusting your treatment plan if needed, and answering any questions you may have about your condition or care.

21 services20 patients

Colorectal cancer screening; colonoscopy on individual not meeting criteria for high risk G0121

Colorectal cancer screening, such as a colonoscopy, is a preventive measure to detect early signs of cancer in the large intestine. For individuals not at high risk, it's typically recommended at age 50. A small, flexible tube with a camera is used to examine your colon. It's a safe, effective way to catch issues early.

19 services19 patients

Diagnostic exam of large bowel using a flexible endoscope 45378

This procedure, known as a colonoscopy, involves using a flexible tube with a light and camera to examine the large intestine. It helps detect any abnormalities such as polyps or inflammation. It's a standard procedure to ensure gut health.

16 services16 patients

Diagnostic exam of esophagus, stomach, and/or upper small bowel using a flexible endoscope 43235

This procedure, known as an upper endoscopy, involves inserting a thin, flexible tube with a camera down the throat to examine the esophagus, stomach, and upper small bowel. It helps diagnose conditions like ulcers or inflammation.

12 services12 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94546 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient

$153.83 typical visit price

range $69.00 – $202.35

Typical copayment $38.45 (range $17.25 – $50.58)

Most-billed visit code 99204

Established Patient

$119.48 typical visit price

range $23.44 – $166.46

Typical copayment $29.87 (range $5.86 – $41.61)

Most-billed visit code 99214

Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Medicare Quality Performance CMS QPP · MIPS

Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.

80.9/100

MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program

Individually scored

Quality

73.03

Promoting Interoperability

Improvement Activities

Cost

58.32

Reported Quality Measures

Breast Cancer Screening

5%273 patients1/55-star benchmark: 93%

Cervical Cancer Screening

29%188 patients2/55-star benchmark: 98%

Colorectal Cancer Screening

67%621 patients4/55-star benchmark: 88%

Controlling High Blood Pressure

29%220 patients2/55-star benchmark: 91%

Diabetes: Eye Exam

1%89 patients1/55-star benchmark: 100%

Diabetes: Hemoglobin A1c (HbA1c) Poor Control (>9%)

Lower rates are better for this measure.

81%89 patients1/55-star benchmark: 91%

Documentation of Current Medications in the Medical Record

99%1,263 patients4/55-star benchmark: 100%

e-Prescribing

97%1,294 patients4/55-star benchmark: 100%

Falls: Screening for Future Fall Risk

7%502 patients1/55-star benchmark: 100%

Preventive Care and Screening: Body Mass Index (BMI) Screening and Follow-Up Plan

26%923 patients2/55-star benchmark: 98%

Preventive Care and Screening: Screening for Depression and Follow-Up Plan

5%865 patients1/55-star benchmark: 97%

Preventive Care and Screening: Screening for High Blood Pressure and Follow-Up Documented

6%804 patients1/55-star benchmark: 61%

Preventive Care and Screening: Tobacco Use: Screening and Cessation Intervention

Patients screened: 95% · 245 patients

91%245 patients

Provide Patients Electronic Access to Their Health Information

26%1,196 patients1/55-star benchmark: 100%

Statin Therapy for the Prevention and Treatment of Cardiovascular Disease

86%148 patients4/55-star benchmark: 91%

Use of High-Risk Medications in Older Adults

Lower rates are better for this measure.

Patients appropriateDiagnosis: 1% · 530 patients

Patients totalRate: 2% · 530 patients

2%530 patients4/55-star benchmark: 100%

Providers report different measures because they deliver different services; reporting more or less information is not a reflection of quality. Star ratings appear only where CMS assigned them.

Other Providers at the Same Location NPPES 20

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

ALAN R. SILVERMAN M.D. INC

Family Medicine

19845 LAKE CHABOT RD, SUITE 301
CASTRO VALLEY, CA 94546

Alameda County (510) 881-5203

VISHAL GHEVARIYA M.D.

Internal Medicine (Gastroenterology)

19845 LAKE CHABOT RD, STE 104
CASTRO VALLEY, CA 94546

Alameda County (510) 537-4415

DR. CAROLYN ELIZABETH MCALOON DPM

Podiatrist (Foot & Ankle Surgery)

19845 LAKE CHABOT RD, SUITE 301
CASTRO VALLEY, CA 94546

Alameda County (510) 581-1484

GEORGE D COWEN, MD PROFESSIONAL CORP

Internal Medicine

19845 LAKE CHABOT RD, SUITE 211
CASTRO VALLEY, CA 94546

Alameda County (510) 582-6966

MR. JEAN-PIERRE LOUIS VIEL PT, DPT, OCS

Physical Therapist

19845 LAKE CHABOT RD, SUITE 205
CASTRO VALLEY, CA 94546

Alameda County (510) 538-9558

DR. AMBER LOUISE JONES D.O., M.P.H.

Surgery (Trauma Surgery)

19845 LAKE CHABOT RD
CASTRO VALLEY, CA 94546

Alameda County (510) 538-5500

DR. TERENCE CHUCK WONG D.D.S.

Dentist (General Practice)

19845 LAKE CHABOT RD, SUITE #210
CASTRO VALLEY, CA 94546

Alameda County (510) 581-7788

SARAH H LINDAHL PAC

Physician Assistant

19845 LAKE CHABOT RD, SUITE #302
CASTRO VALLEY, CA 94546

Alameda County (510) 886-3400

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Wei-fang Ko's NPI number?

The NPI number for Wei-fang Ko is 1417068081. It was assigned to this individual provider in the NPPES registry on August 31, 2006.

Where is Wei-fang Ko located?

Wei-fang Ko practices at 19845 Lake Chabot Rd Suite, 104, Castro Valley, CA 94546. The listed phone number is (510) 537-4415.

What is Wei-fang Ko's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.

Is Wei-fang Ko enrolled in Medicare?

Yes. Wei-fang Ko is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Which organizations bill Medicare for Wei-fang Ko's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Wei-fang Ko reassigns Medicare benefits to 2 organizations: Gastroenterology Specialists Medical Group, Inc A Medical Corporation (Castro Valley, CA) and Genesis Healthcare Partners PC (Encinitas, CA). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Wei-fang Ko's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for Wei-fang Ko was last updated on August 1, 2022. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.