GREGORY M KEELEN DO
NPI 1811905227
Emergency Medicine in Denison, TX
About Gregory M Keelen Do NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
GREGORY M KEELEN DO (NPI 1811905227) is an individual emergency medicine provider in Denison, Texas, licensed in Texas (M1822) and active in the NPI registry since August 2006. He is enrolled in Medicare PECOS, is affiliated with Saint Francis Hospital Muskogee, and is a graduate of University Of Kansas School Of Med (kc/wich/sal) (2003).
NPPES Registry Identity
Specialties & Licenses
Other Identifiers 3
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
Gregory M Keelen 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
4Medicare enrollment records show Gregory Keelen reassigns Medicare billing to 4 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Denison, TX 75020
- Reassigned Medicare billing, Texas enrollment
- 67 clinicians in this Medicare group
Hillsboro, TX 76645
- Reassigned Medicare billing, Texas enrollment
- 127 clinicians in this Medicare group
Tulsa, OK 74136
- Reassigned Medicare billing, Oklahoma enrollment
- 263 clinicians in this Medicare group
Amarillo, TX 79106
- Reassigned Medicare billing, Texas enrollment
- 66 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 4
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Saint Francis Hospital Muskogee
Acute Care Hospitals · Muskogee, OKSaint Francis Hospital, Inc
Acute Care Hospitals · Tulsa, OKSaint Francis Hospital South, LLC
Acute Care Hospitals · Tulsa, OKTexoma Medical Center
Acute Care Hospitals · Denison, TXPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 75020 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
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 Gregory Keelen's NPI number?
The NPI number for Gregory Keelen is 1811905227. It was assigned to this individual provider in the NPPES registry on August 3, 2006.
Where is Gregory Keelen located?
Gregory Keelen practices at 5016 Us-75 Tmc Emergency Department, Denison, TX 75020. The listed phone number is (214) 433-9602.
What is Gregory Keelen's specialty?
The primary specialty registered for this NPI is Emergency Medicine with taxonomy code 207P00000X.
Is Gregory Keelen enrolled in Medicare?
Yes. Gregory Keelen 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 Gregory Keelen's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Gregory Keelen reassigns Medicare benefits to 4 organizations: Level One Emergency Physicians LLC (Denison, TX), Ies Central Texas PLLC (Hillsboro, TX), Ies ER Oklahoma LLC (Tulsa, OK) and Truepartners Northwest Emergency Associates PLLC (Amarillo, 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 Gregory Keelen's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Gregory Keelen accept?
Health plans from Blue Cross and Blue Shield of Texas list Gregory Keelen 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 Gregory Keelen affiliated with any hospitals?
According to CMS data, Gregory Keelen is affiliated with Saint Francis Hospital Muskogee, Saint Francis Hospital, Inc, Saint Francis Hospital South, LLC and Texoma Medical Center.
When was this NPI record last updated?
The NPPES record for Gregory Keelen was last updated on January 22, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 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.
# Gregory M Keelen, DO · NPI 1811905227
Emergency Medicine physician in Denison, Texas. Individual provider, active in the CMS NPPES registry since August 3, 2006.
## Identity
- **NPI:** 1811905227 (Entity type: Individual)
- **Enumerated:** August 3, 2006
- **Primary specialty:** Emergency Medicine · taxonomy 207P00000X
- **State license:** M1822 (Texas)
- **Sole proprietor:** No
## Practice location
- **Address:** 5016 US-75, TMC EMERGENCY DEPARTMENT, Denison, TX 75020
- **Phone:** (214) 433-9602 · **Fax:** (214) 433-9602
## 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:** 4 organizations under Medicare reassignment (form CMS-855R): Level One Emergency Physicians LLC (NPI 1528790193, Denison, TX); Ies Central Texas PLLC (NPI 1003523002, Hillsboro, TX); Ies ER Oklahoma LLC (NPI 1447148093, Tulsa, OK); Truepartners Northwest Emergency Associates PLLC (NPI 1912447319, Amarillo, TX) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of Kansas School Of Med, class of 2003
## Record status
- **NPPES last updated:** January 22, 2024
- **Other identifiers:** Other P00312435 (TX); Medicaid 188205201 (TX); Other 8V3644 (TX)
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Source: [NPI Profile](https://npiprofile.com/npi/1811905227) · Data from the CMS NPPES public registry.