CHIH YAO CHANG MD
NPI 1730820739
Internal Medicine in San Francisco, CA

Active since April 05, 2022PECOS EnrolledAccepts Medicare Assignment
521 PARNASSUS AVE, SAN FRANCISCO, CA 94143(415) 750-5942(415) 750-5594 Get Directions Write a Review

NPPES record last updated: May 15, 2025. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: May 15, 2025, Mar 5, 2023, Apr 5, 2022 (3 updates tracked since 2022).

About Chih Yao Chang Md NPPES

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

CHIH YAO CHANG MD (NPI 1730820739) is an individual internal medicine provider in San Francisco, California, licensed in California (A199655) and active in the NPI registry since April 2022. He is enrolled in Medicare PECOS, maintains a secondary practice location in San Francisco, and is a graduate of Other (2019).

NPPES Registry Identity

NPI1730820739
Entity TypeIndividualMale
Primary Taxonomy207R00000X
Provider Legal NameCHIH YAO CHANGCredential: MD
Location Address521 PARNASSUS AVESan Francisco, CA 94143-2206
Mailing Address521 Parnassus AveSan Francisco, CA 94143-2206 · (415) 750-5942 · Fax (415) 750-5594
Fax(415) 750-5594
Sole ProprietorNo
Medical School CMSOtherGraduated 2019
Enumeration DateApril 5, 2022
Last NPPES UpdateMay 15, 20253 updates tracked since enumeration
NPPES CertifiedMay 15, 2025
✔ NPI 1730820739 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in CA · A199655
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.
521 PARNASSUS AVE, San Francisco, CA 94143

Other Names 1

Other Name (5)Jeffrey Chang Md

Secondary Practice Location 1

Location 1St. Mary's Medical Center, 450 Stanyan StreetSan Francisco, CA 94117 · Phone (415) 750-5942 · Fax (415) 750-5594

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

Chih Yao Chang Md 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 ID7416475470
PECOS Enrollment IDI20250514001695
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

3

Medicare enrollment records show Chih Yao Chang reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Endocrinology, Diabetes & Metabolism
505 PARNASSUS AVE
San Francisco, CA 94143
  • Reassigned Medicare billing, California enrollment
  • 2,112 clinicians in this Medicare group
Surgery
400 PARNASSUS AVE, MCB 300
San Francisco, CA 94143
  • Reassigned Medicare billing, California enrollment
  • 5,645 clinicians in this Medicare group
Internal Medicine
400 PARNASSUS AVE
San Francisco, CA 94122
  • Reassigned Medicare billing, California enrollment
  • 5,544 clinicians in this Medicare group

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

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94143 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.

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.

Counselor (Pastoral)
521 PARNASSUS AVE
SAN FRANCISCO, CA 94143
Oral & Maxillofacial Surgery
521 PARNASSUS AVE, C-522
SAN FRANCISCO, CA 94143
Hospitalist
521 PARNASSUS AVE
SAN FRANCISCO, CA 94143
Hospitalist
521 PARNASSUS AVE
SAN FRANCISCO, CA 94143
Hospitalist
521 PARNASSUS AVE
SAN FRANCISCO, CA 94143
Anesthesiology
521 PARNASSUS AVE
SAN FRANCISCO, CA 94143
Anesthesiology
521 PARNASSUS AVE
SAN FRANCISCO, CA 94143
Anesthesiology
521 PARNASSUS AVE, RM C-450
SAN FRANCISCO, CA 94143

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 Chih Yao Chang's NPI number?

The NPI number for Chih Yao Chang is 1730820739. It was assigned to this individual provider in the NPPES registry on April 5, 2022. The provider is also known as Jeffrey Chang MD.

Where is Chih Yao Chang located?

Chih Yao Chang practices at 521 Parnassus Ave, San Francisco, CA 94143. The listed phone number is (415) 750-5942.

What is Chih Yao Chang's specialty?

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

Is Chih Yao Chang enrolled in Medicare?

Yes. Chih Yao 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 Chih Yao Chang's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Chih Yao Chang reassigns Medicare benefits to 3 organizations: Regents Of The University Of California (San Francisco, CA), University Of California San Francisco (San Francisco, CA) and Ucsf Medical Group Business Services (San Francisco, 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 Chih Yao 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 Chih Yao Chang was last updated on May 15, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 17 months 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.