Mary Kay Larson, APN
Nurse Practitioner · Warrenville, IL
Mary Kay Larson, APN is a nurse practitioner with a practice address in Warrenville, Illinois, and NPI 1124293691, issued on Apr 25, 2008. Check the license (Illinois 209006678, as entered in NPPES) with the Illinois board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Mary Kay Larson
- Credential
- APN
- Primary taxonomy
- Nurse Practitioner 363L00000X
- License number
- 209006678 IL
Self-reported in NPPES; status is on the state search - Practice location
- 4405 Weaver Pkwy, Warrenville, IL 60555
- Phone
- (630) 352-5450
- Enumerated
- Apr 25, 2008
- Record last updated
- Apr 22, 2013 (not updated in 13 years: call before relying on the address or phone)
- Fax
- (630) 352-5499
- Medicare enrollment
- Enrolled (PECOS I20260327001377); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest nurse practitioner records → All 4,892 in Illinois → Look up another NPI →
Also registered at 4405 Weaver Pkwy
A shared address usually means a shared clinic or building; it does not show who employs whom.
- John Abad, M.D.Surgical Oncology Physician1578722336
- Raanan Alter, MDGynecologic Oncology Physician1558789826
- John Ayers, MDHematology & Oncology Physician1477540821
- Madeline BiceNurse Practitioner1982189221
- Mackenzie Blackburn, APRN, CNPNurse Practitioner1740005511
- Robin Buerki, MDNeurology Physician1881936326
Verify Mary Kay Larson in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich Illinois board licenses this profession
Search for license 209006678Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
94% fewer Medicare Part D claims than the average nurse practitioner in 2024
64 Medicare Part D claims for 21 beneficiaries, against an average of 1,109 among the 54,319 providers of this specialty who prescribed in Part D.
Most prescribed
- Clotrimazole11 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Mary Kay Larson among 4,892 nurse practitioner records in Illinois
Mary Kay Larson, APN is one of 4,892 nurse practitioner records with a practice address in Illinois. 81% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2008, is newer than 15% of them.
- NPI issued2008 · 15% of these records are older, 83% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 69% of these records are
- Graduated2006 · median 2018 among the 3,389 with a school on file
- Record last updated2013 · 36% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 363L00000X and a Illinois practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
22 nurse practitioner records list a practice address in Warrenville
They are 22 of the 517 NPPES records with a practice address in Warrenville, and 4,892 nurse practitioner records in Illinois.
All 4,892 in Illinois → Every provider in Warrenville → Nurse Practitioner nationwide →
The 8 nurse practitioner records with the nearest ZIP codes
- Madeline BiceWarrenville, IL 605551982189221
- Tonia Cabai, NP-CWarrenville, IL 605551245684018
- Marjorie Delaney, NPWarrenville, IL 605551649354069
- Brittany GraftWarrenville, IL 605551205373461
- Angela Gryzbek, M.S.N.Warrenville, IL 605551144616327
- Sherry Henricks, APN-CNPWarrenville, IL 605551841422623
- Sarah Knobbe, FNP-BCWarrenville, IL 605551578032546
- Christine Pontarelli, APRN, CNPWarrenville, IL 605551508401175
Common questions
What is Mary Kay Larson, APN's NPI number?
Mary Kay Larson, APN's National Provider Identifier (NPI) is 1124293691, issued on Apr 25, 2008. An NPI identifies a provider in billing; it is not a license.
Where is Mary Kay Larson, APN located?
The NPPES record lists a practice address at 4405 Weaver Pkwy, Warrenville, IL, 60555. Phone: (630) 352-5450. Providers update this record themselves, so call before visiting.
How can I verify Mary Kay Larson, APN's license?
NPPES lists Illinois license number 209006678, as entered by the provider. Search the Illinois board that licenses this profession; the NPPES record confirms identity only.
How much does Mary Kay Larson, APN prescribe under Medicare Part D?
In 2024, Mary Kay Larson, APN had 64 Medicare Part D claims for 21 beneficiaries; the average among nurse practitioner prescribers was 1,109. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.