MARY KAY LARSON APN
NPI 1124293691
Nurse Practitioner in Warrenville, IL
About Mary Kay Larson Apn NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MARY KAY LARSON APN (NPI 1124293691) is an individual nurse practitioner in Warrenville, Illinois, licensed in Illinois (209006678) and active in the NPI registry since April 2008. She is enrolled in Medicare PECOS and is a graduate of Other (2006).
NPPES Registry Identity
Specialties & Licenses
Other Identifiers 1
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
Mary Kay Larson Apn 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 Mary Kay Larson reassigns Medicare billing to 4 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Carol Stream, IL 60122
- Reassigned Medicare billing, Illinois enrollment
- 1,664 clinicians in this Medicare group
Oakbrook Terrace, IL 60181
- Reassigned Medicare billing, Illinois enrollment
- 189 clinicians in this Medicare group
Chicago, IL 60612
- Reassigned Medicare billing, Illinois enrollment
- 127 clinicians in this Medicare group
Nashville, TN 37214
- Reassigned Medicare billing, Missouri, Nebraska, Ohio, South Dakota and Virginia enrollments
- 26 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 60555 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.
WARRENVILLE, IL 60555
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 Mary Kay Larson's NPI number?
The NPI number for Mary Kay Larson is 1124293691. It was assigned to this individual provider in the NPPES registry on April 25, 2008.
Where is Mary Kay Larson located?
Mary Kay Larson practices at 4405 Weaver Pkwy, Warrenville, IL 60555. The listed phone number is (630) 352-5450.
What is Mary Kay Larson's specialty?
The primary specialty registered for this NPI is Nurse Practitioner with taxonomy code 363L00000X.
Is Mary Kay Larson enrolled in Medicare?
Yes. Mary Kay Larson 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 Mary Kay Larson's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Mary Kay Larson reassigns Medicare benefits to 4 organizations: Central Dupage Physician Group (Carol Stream, IL), Vpa PC (Oakbrook Terrace, IL), MD @ Home Illinois, Sc (Chicago, IL) and Carelon Medical Partners, PC (Nashville, TN). 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 Mary Kay Larson's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
When was this NPI record last updated?
The NPPES record for Mary Kay Larson was last updated on September 29, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 21 days 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.
# Mary Kay Larson, APN · NPI 1124293691
Nurse Practitioner physician in Warrenville, Illinois. Individual provider, active in the CMS NPPES registry since April 25, 2008.
## Identity
- **NPI:** 1124293691 (Entity type: Individual)
- **Enumerated:** April 25, 2008
- **Primary specialty:** Nurse Practitioner · taxonomy 363L00000X
- **State license:** 209006678 (Illinois)
- **Sole proprietor:** No
## Practice location
- **Address:** 4405 WEAVER PKWY, Warrenville, IL 60555-3269
- **Phone:** (630) 352-5450 · **Fax:** (630) 352-5499
## 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): Central Dupage Physician Group (NPI 1033149844, Carol Stream, IL); Vpa PC (NPI 1174925663, Oakbrook Terrace, IL); MD @ Home Illinois, Sc (NPI 1568758415, Chicago, IL); Carelon Medical Partners, PC (NPI 1124443403, Nashville, TN) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2006
## Record status
- **NPPES last updated:** September 29, 2026
- **Other identifiers:** Other 206147214 (IL)
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Source: [NPI Profile](https://npiprofile.com/npi/1124293691) · Data from the CMS NPPES public registry.