Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

Dr. Mary Ellen Chang, DO

Individual provider Student in an Organized Health Care Education/Training Program · NPI 1649891987

Dr. Mary Ellen Chang, DO is an Emergency Medicine in San Antonio, Texas. Qualified in 2020, 6 years ago. Practices with Ies ER Oklahoma LLC, a 128-clinician group and accepts Medicare assignment. Licensed in Texas.

Years since qualifying
6
Licensed in
TX
In the registry since
2020
Specialties on file
2
What do these letters mean?
DO — Doctor of Osteopathic Medicine
A fully licensed physician, trained like an MD with additional musculoskeletal training. Equivalent practice rights in all 50 states.

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Practice location Address checks out

Student / training record This NPI belongs to someone enrolled in a health care training programme. It carries no licence and no practice of its own, so no address or phone number is published for it.

San Antonio, TX

No coordinates on file. Search this address in Google Maps

Specialties & licences

Emergency Medicine Physician (primary) Taxonomy 207P00000X · Licence T7889 (TX)
Student in an Organized Health Care Education/Training Program Taxonomy 390200000X · Licence BP10070592 (TX)

Record details

NPI number1649891987
Entity typeIndividual (Type 1)
GenderFemale
Credentials DO
Sole proprietorNo
NPI enumeratedApril 28, 2020
Last updated in NPPESJuly 8, 2022
Certification dateJuly 8, 2022

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyEMERGENCY MEDICINE
Medical schoolOTHER
Graduated 2020 (6 years in practice)
Group practice Ies Er Oklahoma Llc — 128 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

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