DR. THERESA ANN DAY M.D.
NPI 1881072007
Family Medicine - Geriatric Medicine in Houston, TX
About Dr. Theresa Ann Day M.d. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. THERESA ANN DAY M.D. (NPI 1881072007) is an individual geriatric medicine provider in Houston, Texas, licensed in Texas (U1177) and active in the NPI registry since May 2015. She is enrolled in Medicare PECOS, is affiliated with Houston Methodist Hospital, and is a graduate of University Of Arizona College Of Medicine (2015).
NPPES Registry Identity
Specialties & Licenses
Other Names 1
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. Theresa Ann Day 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.
Medicare Billing Reassignments
2Medicare enrollment records show Theresa Day reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Houston, TX 77030
- Reassigned Medicare billing, Texas enrollment
- 2,407 clinicians in this Medicare group
Houston, TX 77030
- Reassigned Medicare billing, Texas enrollment
- 1,579 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.
Hospital Affiliations CMS Care Compare
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Houston Methodist Hospital
Acute Care Hospitals · Houston, TXPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 77030 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 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
HOUSTON, TX 77030
HOUSTON, TX 77030
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 Theresa Day's NPI number?
The NPI number for Theresa Day is 1881072007. It was assigned to this individual provider in the NPPES registry on May 7, 2015. The provider is also known as Dr. Theresa Ann Day M.D..
Where is Theresa Day located?
Theresa Day practices at 6550 Fannin St, Houston, TX 77030. The listed phone number is (346) 238-7003.
What is Theresa Day's specialty?
The primary specialty registered for this NPI is Family Medicine, specializing in Geriatric Medicine, with taxonomy code 207QG0300X.
Is Theresa Day enrolled in Medicare?
Yes. Theresa Day 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 Theresa Day's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Theresa Day reassigns Medicare benefits to 2 organizations: Tmh Physician Associates PLLC (Houston, TX) and Houston Methodist Specialty Physicians (Houston, TX). 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 Theresa Day's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
Is Theresa Day affiliated with any hospitals?
According to CMS data, Theresa Day is affiliated with Houston Methodist Hospital.
When was this NPI record last updated?
The NPPES record for Theresa Day was last updated on July 31, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 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.
# Dr. Theresa Ann Day, M.D. · NPI 1881072007
Geriatric Medicine physician in Houston, Texas. Individual provider, active in the CMS NPPES registry since May 7, 2015.
## Identity
- **NPI:** 1881072007 (Entity type: Individual)
- **Enumerated:** May 7, 2015
- **Primary specialty:** Family Medicine - Geriatric Medicine · taxonomy 207QG0300X
- **State license:** U1177 (Texas)
- **Sole proprietor:** No
## Practice location
- **Address:** 6550 FANNIN ST, Houston, TX 77030-2717
- **Phone:** (346) 238-7003
## 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:** 2 organizations under Medicare reassignment (form CMS-855R): Tmh Physician Associates PLLC (NPI 1275779225, Houston, TX); Houston Methodist Specialty Physicians (NPI 1902614332, Houston, TX) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of Arizona College Of Medicine, class of 2015
## Record status
- **NPPES last updated:** July 31, 2026
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Source: [NPI Profile](https://npiprofile.com/npi/1881072007) · Data from the CMS NPPES public registry.