MACKENZIE ANNE SMITH STECK MD
NPI 1619436441
Internal Medicine - Critical Care Medicine in Saint Louis, MO
About Mackenzie Anne Smith Steck Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MACKENZIE ANNE SMITH STECK MD (NPI 1619436441) is an individual critical care medicine provider in Saint Louis, Missouri, licensed in Missouri (2022033891) and active in the NPI registry since March 2019. She is enrolled in Medicare PECOS, is affiliated with Ssm Health St Mary's Hospital - St Louis, and maintains a secondary practice location in Saint Louis.
NPPES Registry Identity
Specialties & Licenses 3
Secondary Practice Location 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
Mackenzie Anne Smith Steck Md 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
3Medicare enrollment records show Mackenzie Steck reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Saint Louis, MO 63104
- Reassigned Medicare billing, Missouri enrollment
- 1,294 clinicians in this Medicare group
Saint Louis, MO 63110
- Reassigned Medicare billing, Missouri enrollment
- 194 clinicians in this Medicare group
Fenton, MO 63026
- Reassigned Medicare billing, Missouri enrollment
- 697 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 3
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Ssm Health St Mary's Hospital - St Louis
Acute Care Hospitals · Richmond Heights, MOSsm Health Saint Louis University Hospital
Acute Care Hospitals · Saint Louis, MOSsm St Joseph Hospital West
Acute Care Hospitals · Lake Saint Louis, MOPhysician 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.
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.
SAINT LOUIS, MO 63104
SAINT 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 Mackenzie Steck's NPI number?
The NPI number for Mackenzie Steck is 1619436441. It was assigned to this individual provider in the NPPES registry on March 19, 2019.
Where is Mackenzie Steck located?
Mackenzie Steck practices at 1225 S Grand Blvd, Saint Louis, MO 63104. The listed phone number is (314) 977-4680.
What is Mackenzie Steck's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Critical Care Medicine, with taxonomy code 207RC0200X.
Is Mackenzie Steck enrolled in Medicare?
Yes. Mackenzie Steck 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 Mackenzie Steck's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Mackenzie Steck reassigns Medicare benefits to 3 organizations: Ssm Health Care Group (Saint Louis, MO), Slh Physicians LLC (Saint Louis, MO) and Ssm Medical Group, Inc. (Fenton, 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 Mackenzie Steck's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Mackenzie Steck accept?
Health plans from Anthem Blue Cross and Blue Shield, Medica and Oscar Insurance Company list Mackenzie Steck 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 Mackenzie Steck affiliated with any hospitals?
According to CMS data, Mackenzie Steck is affiliated with Ssm Health St Mary's Hospital - St Louis, Ssm Health Saint Louis University Hospital and Ssm St Joseph Hospital West.
When was this NPI record last updated?
The NPPES record for Mackenzie Steck was last updated on April 28, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 6 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.
# Mackenzie Anne Smith Steck, MD · NPI 1619436441
Critical Care Medicine physician in Saint Louis, Missouri. Individual provider, active in the CMS NPPES registry since March 19, 2019.
## Identity
- **NPI:** 1619436441 (Entity type: Individual)
- **Enumerated:** March 19, 2019
- **Primary specialty:** Internal Medicine - Critical Care Medicine · taxonomy 207RC0200X
- **State license:** 2022033891 (Missouri)
- **Sole proprietor:** No
## Practice location
- **Address:** 1225 S GRAND BLVD, Saint Louis, MO 63104-1016
- **Phone:** (314) 977-4680
## 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:** 3 organizations under Medicare reassignment (form CMS-855R): Ssm Health Care Group (NPI 1306589544, Saint Louis, MO); Slh Physicians LLC (NPI 1881668051, Saint Louis, MO); Ssm Medical Group, Inc. (NPI 1700966207, Fenton, MO) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Indiana University School Of Medicine, class of 2019
## Record status
- **NPPES last updated:** April 28, 2026
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Source: [NPI Profile](https://npiprofile.com/npi/1619436441) · Data from the CMS NPPES public registry.