Quick answers
- Where does Mark J. Chang see patients?
- Medicare's clinician data lists 1 practice location in Upland, CA. Call before your visit to confirm the address.
- What is Mark J. Chang's specialty?
- Medicare lists Hematology/Oncology as the primary specialty.
- Does Mark J. Chang accept Medicare assignment?
- Yes. Medicare's clinician data says Mark J. Chang accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- What is the phone number for Mark J. Chang?
- (909) 949-2242, as listed in official Medicare / NPI Registry data.
- What is Mark J. Chang's NPI number?
- 1861954182. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Practice locations
Addresses where Mark J. Chang is enrolled with Medicare (CMS data updated 2026-10-02).
- 1100 San Bernardino Rd, Suite 1100Upland, CA 91786 (909) 949‑2242
Group practices
Medicare enrollment lists Mark J. Chang as a member of this group (CMS data updated 2026-10-02).
- City of Hope Medical Foundation982 clinicians in the group
Specialties
- Hematology/Oncologyprimary
Other hematologist-oncologists in Upland
Clinicians with the same Medicare primary specialty in Upland, CA — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Graduation year | 2019 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1861954182 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians