MRS. MICHELLE MARIE KOESTER WHNP
NPI 1881962843
Nurse Practitioner in Saint Peters, MO
About Mrs. Michelle Marie Koester Whnp NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MRS. MICHELLE MARIE KOESTER WHNP (NPI 1881962843) is an individual nurse practitioner in Saint Peters, Missouri, licensed in Missouri (2000147926) and active in the NPI registry since December 2011. She is enrolled in Medicare PECOS, is affiliated with Mercy Hospital South, and maintains a secondary practice location in Saint Louis.
NPPES Registry Identity
Specialties & Licenses 2
Secondary Practice Location 1
Other Identifiers 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
Mrs. Michelle Marie Koester Whnp 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 Michelle Koester reassigns Medicare billing to 4 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Bridgeton, MO 63044
- Reassigned Medicare billing, Missouri enrollment
- 301 clinicians in this Medicare group
Saint Louis, MO 63141
- Reassigned Medicare billing, Missouri enrollment
- 64 clinicians in this Medicare group
Saint Louis, MO 63141
- Reassigned Medicare billing, Missouri enrollment
- 611 clinicians in this Medicare group
Saint Louis, MO 63128
- Reassigned Medicare billing, Missouri enrollment
- Medicare enrollment name: St Anthonys Physician Organization Hospitalist Services Lc
- 340 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
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Mercy Hospital South
Acute Care Hospitals · Saint Louis, MOPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 63376 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 19
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
SAINT PETERS, MO 63376
SAINT PETERS, MO 63376
SAINT PETERS, MO 63376
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 Michelle Koester's NPI number?
The NPI number for Michelle Koester is 1881962843. It was assigned to this individual provider in the NPPES registry on December 6, 2011.
Where is Michelle Koester located?
Michelle Koester practices at 201 Bjc Saint Peters Dr Ste 200, Saint Peters, MO 63376. The listed phone number is (636) 916-9615.
What is Michelle Koester's specialty?
The primary specialty registered for this NPI is Nurse Practitioner with taxonomy code 363L00000X.
Is Michelle Koester enrolled in Medicare?
Yes. Michelle Koester 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 Michelle Koester's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Michelle Koester reassigns Medicare benefits to 4 organizations: Sound Physicians Of Illinois, LLC (Bridgeton, MO), Mercy Womens Services LLC (Saint Louis, MO), Physician Groups Lc (Saint Louis, MO) and St Anthonys Physician Organization Hospitalist Services, L.C. (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 Michelle Koester's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Michelle Koester accept?
Health plans from UnitedHealthcare list Michelle Koester 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 Michelle Koester affiliated with any hospitals?
According to CMS data, Michelle Koester is affiliated with Mercy Hospital South.
When was this NPI record last updated?
The NPPES record for Michelle Koester was last updated on January 29, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 9 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.
# Mrs. Michelle Marie Koester, WHNP · NPI 1881962843
Nurse Practitioner physician in Saint Peters, Missouri. Individual provider, active in the CMS NPPES registry since December 6, 2011.
## Identity
- **NPI:** 1881962843 (Entity type: Individual)
- **Enumerated:** December 6, 2011
- **Primary specialty:** Nurse Practitioner · taxonomy 363L00000X
- **State license:** 2000147926 (Missouri)
- **Sole proprietor:** No
## Practice location
- **Address:** 201 BJC SAINT PETERS DR STE 200, Saint Peters, MO 63376-3386
- **Phone:** (636) 916-9615 · **Fax:** (636) 916-9850
## 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): Sound Physicians Of Illinois, LLC (NPI 1043598865, Bridgeton, MO); Mercy Womens Services LLC (NPI 1629327788, Saint Louis, MO); Physician Groups Lc (NPI 1285664268, Saint Louis, MO); St Anthonys Physician Organization Hospitalist Services, L.C. (NPI 1407216336, Saint Louis, MO) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2011
## Record status
- **NPPES last updated:** January 29, 2026
- **Other identifiers:** Medicaid 420012381 (MO)
---
Source: [NPI Profile](https://npiprofile.com/npi/1881962843) · Data from the CMS NPPES public registry.