MARY E WASSILAK WHNP-BC
NPI 1811138944
Nurse Practitioner in Geneva, IL
About Mary E Wassilak Whnp-bc NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MARY E WASSILAK WHNP-BC (NPI 1811138944) is an individual nurse practitioner in Geneva, Illinois, licensed in Illinois (209006774) and active in the NPI registry since March 2009. She is enrolled in Medicare PECOS, maintains a secondary practice location in Chicago, and is a graduate of University Of Illinois College Of Med (chi/peor/rock/chm-urb) (2007).
NPPES Registry Identity
Specialties & Licenses 3
Secondary Practice Location 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 E Wassilak Whnp-bc 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 Reassignment
Medicare enrollment records show Mary Wassilak reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
Carol Stream, IL 60122
- Reassigned Medicare billing, Illinois enrollment
- 1,664 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 60134 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 5
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
GENEVA, IL 60134
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 Wassilak's NPI number?
The NPI number for Mary Wassilak is 1811138944. It was assigned to this individual provider in the NPPES registry on March 19, 2009.
Where is Mary Wassilak located?
Mary Wassilak practices at 351 Delnor Dr Ste 204, Geneva, IL 60134. The listed phone number is (630) 208-0784.
What is Mary Wassilak's specialty?
The primary specialty registered for this NPI is Nurse Practitioner with taxonomy code 363L00000X.
Is Mary Wassilak enrolled in Medicare?
Yes. Mary Wassilak 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 organization bills Medicare for Mary Wassilak's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Mary Wassilak reassigns Medicare benefits to Central Dupage Physician Group (Carol Stream, IL). The 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 Wassilak'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 Wassilak was last updated on October 6, 2023. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 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.
# Mary E Wassilak, WHNP-BC · NPI 1811138944
Nurse Practitioner physician in Geneva, Illinois. Individual provider, active in the CMS NPPES registry since March 19, 2009.
## Identity
- **NPI:** 1811138944 (Entity type: Individual)
- **Enumerated:** March 19, 2009
- **Primary specialty:** Nurse Practitioner · taxonomy 363L00000X
- **State license:** 209006774 (Illinois)
- **Sole proprietor:** No
## Practice location
- **Address:** 351 DELNOR DR STE 204, Geneva, IL 60134-4226
- **Phone:** (630) 208-0784 · **Fax:** (630) 938-9190
## 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:** Central Dupage Physician Group (NPI 1033149844, Carol Stream, IL), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of Illinois College Of Med, class of 2007
## Record status
- **NPPES last updated:** October 6, 2023
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Source: [NPI Profile](https://npiprofile.com/npi/1811138944) · Data from the CMS NPPES public registry.