MR. ANDREW ZACK AA
NPI 1427793355
Anesthesiologist Assistant in Saint Louis, MO
About Mr. Andrew Zack Aa NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MR. ANDREW ZACK AA (NPI 1427793355) is an individual anesthesiologist assistant in Saint Louis, Missouri, licensed in Missouri (PENDING) and active in the NPI registry since May 2022. He is affiliated with Ssm Health Saint Louis University Hospital and is a graduate of Other (2022).
NPPES Registry Identity
Specialties & Licenses
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
Mr. Andrew Zack Aa 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 Andrew Zack 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 63141
- Reassigned Medicare billing, Missouri enrollment
- 309 clinicians in this Medicare group
Saint Louis, MO 63110
- Reassigned Medicare billing, Missouri enrollment
- 142 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
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
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Ssm Health Saint Louis University Hospital
Acute Care Hospitals · Saint Louis, MOOther 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 63141
SAINT LOUIS, MO 63141
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 Andrew Zack's NPI number?
The NPI number for Andrew Zack is 1427793355. It was assigned to this individual provider in the NPPES registry on May 4, 2022.
Where is Andrew Zack located?
Andrew Zack practices at 615 S New Ballas Rd, Saint Louis, MO 63141. The listed phone number is (636) 386-9224.
What is Andrew Zack's specialty?
The primary specialty registered for this NPI is Anesthesiologist Assistant with taxonomy code 367H00000X.
Is Andrew Zack enrolled in Medicare?
Yes. Andrew Zack 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 Andrew Zack's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Andrew Zack reassigns Medicare benefits to 2 organizations: Western Anesthesiology Associates, Inc. (Saint Louis, MO) and Ssm Health Slu Hospital Anesthesia Physician Billing, LLC (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 Andrew Zack's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
Is Andrew Zack affiliated with any hospitals?
According to CMS data, Andrew Zack is affiliated with Ssm Health Saint Louis University Hospital.
When was this NPI record last updated?
The NPPES record for Andrew Zack was last updated on May 4, 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.
# Mr. Andrew Zack, AA · NPI 1427793355
Anesthesiologist Assistant physician in Saint Louis, Missouri. Individual provider, active in the CMS NPPES registry since May 4, 2022.
## Identity
- **NPI:** 1427793355 (Entity type: Individual)
- **Enumerated:** May 4, 2022
- **Primary specialty:** Anesthesiologist Assistant · taxonomy 367H00000X
- **State license:** PENDING (Missouri)
- **Sole proprietor:** No
## Practice location
- **Address:** 615 S NEW BALLAS RD, Saint Louis, MO 63141-8221
- **Phone:** (636) 386-9224 · **Fax:** (636) 386-7679
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Bills Medicare through:** 2 organizations under Medicare reassignment (form CMS-855R): Western Anesthesiology Associates, Inc. (NPI 1275646754, Saint Louis, MO); Ssm Health Slu Hospital Anesthesia Physician Billing, LLC (NPI 1407232804, Saint Louis, MO) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2022
## Record status
- **NPPES last updated:** May 4, 2022
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Source: [NPI Profile](https://npiprofile.com/npi/1427793355) · Data from the CMS NPPES public registry.