DR. MARY ELLEN CHANG DO
NPI 1649891987
Emergency Medicine in San Antonio, TX
About Dr. Mary Ellen Chang Do NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. MARY ELLEN CHANG DO (NPI 1649891987) is an individual emergency medicine provider in San Antonio, Texas, licensed in Texas (T7889) and active in the NPI registry since April 2020. She is enrolled in Medicare PECOS, is affiliated with Baylor University Medical Center, and is a graduate of Other (2020).
NPPES Registry Identity
Specialties & Licenses 2
Other Names 1
Accepted Insurance
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
Dr. Mary Ellen Chang Do 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.
Medicare Billing Reassignments
5Medicare enrollment records show Mary Ellen Chang reassigns Medicare billing to 5 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Pasadena, TX 77505
- Reassigned Medicare billing, Texas enrollment
- 644 clinicians in this Medicare group
Dallas, TX 75246
- Reassigned Medicare billing, Texas enrollment
- 1,044 clinicians in this Medicare group
Frisco, TX 75033
- Reassigned Medicare billing, Texas enrollment
- 90 clinicians in this Medicare group
Frisco, TX 75033
- Reassigned Medicare billing, Texas enrollment
- 89 clinicians in this Medicare group
Tulsa, OK 74136
- Reassigned Medicare billing, Oklahoma enrollment
- 263 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.
Areas of Expertise CMS Part B claims 5
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.
Hospital Affiliations CMS Care Compare 2
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Baylor University Medical Center
Acute Care Hospitals · Dallas, TXBaylor Scott & White Medical Center At Irving
Acute Care Hospitals · Irving, TXPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 78229 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Other Providers at the Same Location NPPES 2
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
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 Mary Ellen Chang's NPI number?
The NPI number for Mary Ellen Chang is 1649891987. It was assigned to this individual provider in the NPPES registry on April 28, 2020. The provider is also known as Dr. Molly Chang Do.
Where is Mary Ellen Chang located?
Mary Ellen Chang practices at 7703 Floyd Curl Dr # 7736, San Antonio, TX 78229. The listed phone number is (210) 567-4621.
What is Mary Ellen Chang's specialty?
The primary specialty registered for this NPI is Emergency Medicine with taxonomy code 207P00000X.
Is Mary Ellen Chang enrolled in Medicare?
Yes. Mary Ellen 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 Mary Ellen Chang's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Mary Ellen Chang reassigns Medicare benefits to 5 organizations: Integrative Emergency Services Physician Group-Houston PLLC (Pasadena, TX), Century Integrated Partners, Inc (Dallas, TX), El Dorado Urgent Care, PLLC (Frisco, TX), Woodbridge Physicians Staffing Group, PLLC (Frisco, TX) and Ies ER Oklahoma LLC (Tulsa, OK). 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 Mary Ellen Chang's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Mary Ellen Chang accept?
Health plans from Blue Cross and Blue Shield of Texas, Oscar Health, Oscar Insurance Company and WellSense Health Plan list Mary Ellen Chang as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.
Is Mary Ellen Chang affiliated with any hospitals?
According to CMS data, Mary Ellen Chang is affiliated with Baylor University Medical Center and Baylor Scott & White Medical Center At Irving.
When was this NPI record last updated?
The NPPES record for Mary Ellen Chang was last updated on July 8, 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.
# Dr. Mary Ellen Chang, DO · NPI 1649891987
Emergency Medicine physician in San Antonio, Texas. Individual provider, active in the CMS NPPES registry since April 28, 2020.
## Identity
- **NPI:** 1649891987 (Entity type: Individual)
- **Enumerated:** April 28, 2020
- **Primary specialty:** Emergency Medicine · taxonomy 207P00000X
- **State license:** T7889 (Texas)
- **Sole proprietor:** No
## Practice location
- **Address:** 7703 FLOYD CURL DR # 7736, San Antonio, TX 78229-3901
- **Phone:** (210) 567-4621
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 5 organizations under Medicare reassignment (form CMS-855R): Integrative Emergency Services Physician Group-Houston PLLC (NPI 1801458708, Pasadena, TX); Century Integrated Partners, Inc (NPI 1447615711, Dallas, TX); El Dorado Urgent Care, PLLC (NPI 1154799328, Frisco, TX); Woodbridge Physicians Staffing Group, PLLC (NPI 1750777322, Frisco, TX); Ies ER Oklahoma LLC (NPI 1447148093, Tulsa, OK) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2020
## Record status
- **NPPES last updated:** July 8, 2022
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Source: [NPI Profile](https://npiprofile.com/npi/1649891987) · Data from the CMS NPPES public registry.