ALLISON WILLIAMSON CPNP
NPI 1114390663
Nurse Practitioner - Pediatrics in Saint Louis, MO
About Allison Williamson Cpnp NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
ALLISON WILLIAMSON CPNP (NPI 1114390663) is an individual pediatrics provider in Saint Louis, Missouri, licensed in Missouri (2015015186) and active in the NPI registry since November 2015. She is enrolled in Medicare PECOS.
NPPES Registry Identity
Specialties & Licenses
Accepted Insurance
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
Allison Williamson Cpnp is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Medicare Billing Reassignments
2Medicare enrollment records show Allison Williamson reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Saint Louis, MO 63117
- Reassigned Medicare billing, Missouri enrollment
- 741 clinicians in this Medicare group
Saint Louis, MO 63139
- Reassigned Medicare billing, Missouri enrollment
- Medicare enrollment name: Ssm Cardinal Glennon Children's Hospital
- 414 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.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 63104 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.
SAINT LOUIS, MO 63104
SAINT LOUIS, MO 63104
ST.LOUIS, MO 63104
SAINT LOUIS, MO 63104
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 Allison Williamson's NPI number?
The NPI number for Allison Williamson is 1114390663. It was assigned to this individual provider in the NPPES registry on November 5, 2015.
Where is Allison Williamson located?
Allison Williamson practices at 1465 S Grand Blvd, Saint Louis, MO 63104. The listed phone number is (314) 577-5666.
What is Allison Williamson's specialty?
The primary specialty registered for this NPI is Nurse Practitioner, specializing in Pediatrics, with taxonomy code 363LP0200X.
Is Allison Williamson enrolled in Medicare?
Yes. Allison Williamson is registered in the Medicare PECOS enrollment system.
Which organizations bill Medicare for Allison Williamson's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Allison Williamson reassigns Medicare benefits to 2 organizations: Ssm Health Care St. Louis (Saint Louis, MO) and Ssm Cardinal Glennon Childrens Hospital (Saint Louis, MO). 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 Allison Williamson's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Allison Williamson accept?
Health plans from Ambetter Health, Ambetter Health of Delaware, Ambetter from Arkansas Health & Wellness, Ambetter from Sunflower Health Plan and Ambetter of Oklahoma and 4 other insurers list Allison 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.
When was this NPI record last updated?
The NPPES record for Allison Williamson was last updated on November 5, 2015. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 11 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.
# Allison Williamson, CPNP · NPI 1114390663
Pediatrics physician in Saint Louis, Missouri. Individual provider, active in the CMS NPPES registry since November 5, 2015.
## Identity
- **NPI:** 1114390663 (Entity type: Individual)
- **Enumerated:** November 5, 2015
- **Primary specialty:** Nurse Practitioner - Pediatrics · taxonomy 363LP0200X
- **State license:** 2015015186 (Missouri)
- **Sole proprietor:** Yes
## Practice location
- **Address:** 1465 S GRAND BLVD, Saint Louis, MO 63104-1003
- **Phone:** (314) 577-5666
## Medicare
- **Medicare:** Enrolled in Medicare (PECOS)
- **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): Ssm Health Care St. Louis (NPI 1366400855, Saint Louis, MO); Ssm Cardinal Glennon Childrens Hospital (NPI 1073568226, Saint Louis, MO) · CMS Revalidation Reassignment List, October 2026 release
## Record status
- **NPPES last updated:** November 5, 2015
---
Source: [NPI Profile](https://npiprofile.com/npi/1114390663) · Data from the CMS NPPES public registry.