Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

Mrs. Mary Colleen Welles, APN

Individual provider Oncology Clinical Nurse Specialist · NPI 1366768764

Mrs. Mary Colleen Welles, APN is registered under Certified Clinical Nurse Specialist (Cns) in Chicago, Illinois. Graduated from Rush Medical College of Rush University in 1994, 32 years ago. Practices with Northwestern Medical Faculty Foundation, a 4,394-clinician group and accepts Medicare assignment. Licensed in Illinois.

Years since qualifying
32
Trained at
Rush Medical College of Rush University
Licensed in
IL
In the registry since
2010
What do these letters mean?
APN — Advanced Practice Nurse
The umbrella title some states use for nurse practitioners and other advanced practice nurses.

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Practice location Address checks out

676 N Saint Clair St Ste 2125
Chicago, IL 60611-2927 Not confirmed with CMS for 16 years — call before visiting
Phone: (312) 926-5400
Fax: (312) 926-8885
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Oncology Clinical Nurse Specialist (primary) Taxonomy 364SX0200X · Licence 209.002324 (IL)

Record details

NPI number1366768764
Entity typeIndividual (Type 1)
GenderFemale
Credentials APN
Sole proprietorNo
NPI enumeratedApril 12, 2010
Last updated in NPPESApril 12, 2010

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyCERTIFIED CLINICAL NURSE SPECIALIST (CNS)
Medical schoolRUSH MEDICAL COLLEGE OF RUSH UNIVERSITY
Graduated 1994 (32 years in practice)
Group practice Northwestern Medical Faculty Foundation — 4394 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations4 on file with Medicare

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients18
Services billed 54 a service is one billed item, such as a visit, a test or a procedure
Average patient age68

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Food and Beverage $120 1 payment · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at Northwestern Medical Faculty Foundation

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 4394 clinicians in the practice; 12 are shown here.

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