DR. JOHN ANDREW WILLIAMSON M.D.
NPI 1083732176
Radiology - Diagnostic Radiology in Austin, TX
About Dr. John Andrew Williamson M.d. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. JOHN ANDREW WILLIAMSON M.D. (NPI 1083732176) is an individual diagnostic radiology provider in Austin, Texas, licensed in Texas (N3389) and active in the NPI registry since March 2007. He is enrolled in Medicare PECOS, is affiliated with Ascension Seton Medical Center Austin, and is a graduate of Duke University School Of Medicine (1998).
NPPES Registry Identity
Specialties & Licenses
Group Practice 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. John Andrew Williamson 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 John Williamson reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Austin, TX 78727
- Reassigned Medicare billing, Texas enrollment
- 187 clinicians in this Medicare group
Shenandoah, TX 77380
- Reassigned Medicare billing, Texas enrollment
- 1,278 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 42
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 5
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Ascension Seton Medical Center Austin
Acute Care Hospitals · Austin, TXSt David's Medical Center
Acute Care Hospitals · Austin, TXSt David's South Austin Medical Center
Acute Care Hospitals · Austin, TXRound Rock Medical Center
Acute Care Hospitals · Round Rock, TXNorth Austin Medical Center
Acute Care Hospitals · Austin, TXPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 78727 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Medicare Quality Performance CMS QPP · MIPS
Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.
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.
AUSTIN, TX 78727
AUSTIN, TX 78727
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 John Williamson's NPI number?
The NPI number for John Williamson is 1083732176. It was assigned to this individual provider in the NPPES registry on March 27, 2007.
Where is John Williamson located?
John Williamson practices at 12554 Riata Vista Cir, Austin, TX 78727. The listed phone number is (512) 795-5100.
What is John Williamson's specialty?
The primary specialty registered for this NPI is Radiology, specializing in Diagnostic Radiology, with taxonomy code 2085R0202X.
Is John Williamson enrolled in Medicare?
Yes. John Williamson 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 John Williamson's services?
According to the CMS Revalidation Reassignment List (October 2026 release), John Williamson reassigns Medicare benefits to 2 organizations: Austin Radiological Association (Austin, TX) and Singleton Associates PA (Shenandoah, 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 John Williamson's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does John Williamson accept?
Health plans from Baylor Scott and White Health Plan, Blue Cross and Blue Shield of Texas, Harbor Health, Oscar Insurance Company and Sendero Health Plans, Local Nonprofit and 1 other insurer list John Williamson 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 John Williamson affiliated with any hospitals?
According to CMS data, John Williamson is affiliated with Ascension Seton Medical Center Austin, St David's Medical Center, St David's South Austin Medical Center, Round Rock Medical Center and North Austin Medical Center.
When was this NPI record last updated?
The NPPES record for John Williamson was last updated on March 15, 2018. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 8 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.