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GWENDOLEN CHANG M.D.
NPI 1386807402
Internal Medicine in San Leandro, CA

Active since July 09, 2008PECOS EnrolledAccepts Medicare Assignment
13851 E 14TH ST STE 206, SAN LEANDRO, CA 94578(510) 351-9373(510) 351-0616 Get Directions Write a Review

NPPES record last updated: December 4, 2013. Verified against the NPPES registry weekly; last sync: November 01, 2026.

About Gwendolen Chang M.d. NPPES

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

GWENDOLEN CHANG M.D. (NPI 1386807402) is an individual internal medicine provider in San Leandro, California, licensed in California (A106132) and active in the NPI registry since July 2008. She is enrolled in Medicare PECOS and is a graduate of Stanford University School Of Medicine (2007).

NPPES Registry Identity

NPI1386807402
Entity TypeIndividualFemale
Primary Taxonomy207R00000X
Provider Legal NameGWENDOLEN CHANGCredential: M.D.
Location Address13851 E 14TH ST STE 206San Leandro, CA 94578-2627
Mailing Address13851 E 14th St Ste 206San Leandro, CA 94578-2627 · (510) 351-9373 · Fax (510) 351-0616
Phone(510) 351-9373
Fax(510) 351-0616
Sole ProprietorNo
Medical School CMSStanford University School Of MedicineGraduated 2007
Enumeration DateJuly 9, 2008
Last NPPES UpdateDecember 4, 2013
✔ NPI 1386807402 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in CA · A106132
Definition
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.
13851 E 14TH ST STE 206, San Leandro, CA 94578
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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

Gwendolen Chang 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 ID6901095959
PECOS Enrollment IDI20110106000994
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

2

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

Alameda Health System
1.3 mi
Federally Qualified Health Center (FQHC)
15400 FOOTHILL BLVD
San Leandro, CA 94578
  • Reassigned Medicare billing, California enrollment
  • 900 clinicians in this Medicare group
NPI 1558749440 (510) 532-1930
West Coast Kidney
19 mi
Nephrology
2222 EAST ST STE 305
Concord, CA 94520
  • Reassigned Medicare billing, California enrollment
  • 63 clinicians in this Medicare group
NPI 1952914681 (925) 686-1230

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 15

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 moderate level of decision making, if using time, 30 minutes or more 99214
This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.
379 services176 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.
358 services140 patients
Dialysis services, 4 or more physician visits per month (20 years or older) 90960
Dialysis is a treatment that filters and purifies your blood using a machine. It helps keep your fluids and electrolytes in balance when the kidneys can't do their job. This service includes 4 or more visits per month with a physician to monitor your health and adjust your treatment as needed.
258 services40 patients
Chronic care management services, first 20 minutes of clinical staff time directed by health care professional, per calendar month 99490
Chronic care management services involve a healthcare professional directing clinical staff in managing your chronic conditions. This includes the first 20 minutes per month of services like medication management, care coordination, and health monitoring to help improve your health and quality of life.
203 services45 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.
177 services93 patients
Chronic care management services for two or more chronic conditions, additional 20 minutes of clinical staff time directed by health care professional, per calendar month 99439
Chronic Care Management services involve regular check-ins with healthcare professionals to manage two or more chronic conditions. It includes an additional 20 minutes of clinical staff time per month, directed by a healthcare professional, to ensure optimal health management.
127 services45 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94578 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.

Reported Quality Measures

Care Plan
Percentage of patients aged 65 years and older who have an advance care plan or surrogate decision maker documented in the medical record that an advance care plan was discussed but the patient did not wish or was not able to name a surrogate decision maker…
24%161 patients1/55-star benchmark: 100%
Colorectal Cancer Screening
Percentage of adults 50-75 years of age who had appropriate screening for colorectal cancer
1%106 patients1/55-star benchmark: 85%
Documentation of Current Medications in the Medical Record
Percentage of visits for patients aged 18 years and older for which the eligible professional or eligible clinician attests to documenting a list of current medications using all immediate resources available on the date of the encounter.
94%556 patients4/55-star benchmark: 100%
e-Prescribing
At least one permissible prescription written by the MIPS eligible clinician is queried for a drug formulary and transmitted electronically using certified EHR technology.
93%946 patients4/55-star benchmark: 99%
Medication Reconciliation
The MIPS eligible clinician performs medication reconciliation for at least one transition of care in which the patient is transitioned into the care of the MIPS eligible clinician.
96%82 patients4/55-star benchmark: 100%
Patient-Specific Education
The MIPS eligible clinician must use clinically relevant information from CEHRT to identify patient-specific educational resources and provide access to those materials to at least one unique patient seen by the MIPS eligible clinician.
86%218 patients4/55-star benchmark: 97%
Preventive Care and Screening: Body Mass Index (BMI) Screening and Follow-Up Plan
Percentage of patients aged 18 years and older with a BMI documented during the current encounter or during the previous twelve months AND with a BMI outside of normal parameters, a follow-up plan is documented during the encounter or during the previous…
33%210 patients2/55-star benchmark: 97%
Preventive Care and Screening: Influenza Immunization
Percentage of patients aged 6 months and older seen for a visit between October 1 and March 31 who received an influenza immunization OR who reported previous receipt of an influenza immunization
33%211 patients2/55-star benchmark: 88%
Preventive Care and Screening: Tobacco Use: Screening and Cessation Intervention
Percentage of patients aged 18 years and older who were screened for tobacco use one or more times within 24 months AND who received tobacco cessation intervention if identified as a tobacco user
Patients screenedForUse: 98% · 167 patients
Patients tobacco: 33% · 21 patients
89%167 patients4/55-star benchmark: 98%
Provide Patient Access
At least one patient seen by the MIPS eligible clinician during the performance period is provided timely access to view online, download, and transmit to a third party their health information subject to the MIPS eligible clinician's discretion to withhold…
46%218 patients2/55-star benchmark: 100%
Secure Messaging
For at least one unique patient seen by the MIPS eligible clinician during the performance period, a secure message was sent using the electronic messaging function of CEHRT to the patient (or the patient-authorized representative), or in response to a secure…
21%218 patients1/55-star benchmark: 89%
View, Download, or Transmit (VDT)
At least one patient seen by the MIPS eligible clinician during the performance period (or patient-authorized representative) views, downloads or transmits their health information to a third party during the performance period.
10%218 patients
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 3

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

ANNE YU MD
Internal Medicine (Nephrology)
13851 E 14TH ST STE 206
SAN LEANDRO, CA 94578
Alameda County (510) 351-9373
LYDIA G ANDEMARIAM NP
Nurse Practitioner (Family)
13851 E 14TH ST STE 206
SAN LEANDRO, CA 94578
Alameda County (510) 351-9373
MRS. GEE YEN TSOU PA-C
Physician Assistant (Medical)
13851 E 14TH ST STE 206
SAN LEANDRO, CA 94578
Alameda County (510) 351-9373

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 Gwendolen Chang's NPI number?

The NPI number for Gwendolen Chang is 1386807402. It was assigned to this individual provider in the NPPES registry on July 9, 2008.

Where is Gwendolen Chang located?

Gwendolen Chang practices at 13851 E 14th St Ste 206, San Leandro, CA 94578. The listed phone number is (510) 351-9373.

What is Gwendolen Chang's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Gwendolen Chang enrolled in Medicare?

Yes. Gwendolen Chang 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 Gwendolen Chang's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Gwendolen Chang reassigns Medicare benefits to 2 organizations: Alameda Health System (San Leandro, CA) and West Coast Kidney (Concord, 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 Gwendolen Chang'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 Gwendolen Chang was last updated on December 4, 2013. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 12 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.