Mary Wassilak, WHNP-BC
NPI 1811138944 · Nurse Practitioner · Geneva, IL
Enrolled with Medicare as Practitioner - Nurse Practitioner · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mary Wassilak, WHNP-BC is a Nurse Practitioner provider in Geneva, IL (NPI 1811138944).
Provider details
- NPI number
- 1811138944
- Entity type
- Individual
- Primary specialty
- Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- WHNP-BC
- Sex
- Female
- Sole proprietor
- No
- License
- 209.006774 (IL)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Physician Assistants & Advanced Practice Nursing Providers
Physician Assistants & Advanced Practice Nursing Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
17 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
2 documented practice locations
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$103 across 1 record (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Additional practice locations (1)
- 680 N Lake Shore DrSuite 824Chicago, IL 60611-4546Phone: (312) 943-3300Fax: (312) 568-4654
Registry dates
- Enumerated
- 2009-03-19
- Last updated
- 2023-10-06
- Certified
- 2023-10-06
Frequently asked questions
- What is Mary Wassilak's NPI number?
- Mary Wassilak's National Provider Identifier (NPI) is 1811138944, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mary Wassilak's specialty?
- Mary Wassilak is listed in the NPPES registry with a primary specialty of Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Mary Wassilak located?
- Mary Wassilak's practice location on file with NPPES is 351 Delnor Dr Ste 204, Geneva, IL 60134-4226.
- What is Mary Wassilak's phone number?
- The practice phone number listed in the NPPES registry for Mary Wassilak is (630) 208-0784.
- Does Mary Wassilak accept Medicare?
- Mary Wassilak is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mary Wassilak's NPI active?
- Yes — Mary Wassilak's NPI (1811138944) is active in the NPPES registry as of the last update on 2023-10-06.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.