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

William Tillis

Individual provider Pulmonary Disease Physician · NPI 1669468377

William Tillis is a Pulmonary Disease in Lake Geneva, Wisconsin. Graduated from University of Illinois College of Med (CHI/PEOR/ROCK/Chm-Urb) in 1986, 40 years ago. Practices with Mercy Health System Corporation, a 751-clinician group, works from 5 locations and accepts Medicare assignment. Licensed in Illinois, South Carolina and Wisconsin.

Years since qualifying
40
Trained at
University of Illinois College of Med (CHI/PEOR/ROCK/Chm-Urb)
Licensed in
IL, SC, WI
In the registry since
2005
Specialties on file
3

Practice location Address checks out

N2950 State Road 67
Lake Geneva, WI 53147-2655
Phone: (262) 245-0535
Fax: (262) 245-2248
Show map & directions

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Additional practice locations (4)

  • 1001 Main St, Peoria, IL 61606-1907 — (309) 672-5682
  • 1 Richland Medical Park Dr Ste 300, Columbia, SC 29203-6831 — (803) 545-5500
  • 903 Mineral Point Ave, Janesville, WI 53548-2970 — (608) 752-6255
  • 1000 Mineral Point Ave, Janesville, WI 53548-2982 — (608) 756-6868

Specialties & licences

Pulmonary Disease Physician (primary) Taxonomy 207RP1001X · Licence 81911-20 (WI)
Pulmonary Disease Physician Taxonomy 207RP1001X · Licence 83330 (SC)
Pulmonary Disease Physician Taxonomy 207RP1001X · Licence 036085931 (IL)

Record details

NPI number1669468377
Entity typeIndividual (Type 1)
GenderMale
Sole proprietorNo
NPI enumeratedSeptember 27, 2005
Last updated in NPPESSeptember 14, 2023
Certification dateSeptember 14, 2023
Mailing addressN2950 State Road 67, Lake Geneva, WI 53147-2655

Medicare enrollment

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

Medicare specialtyPULMONARY DISEASE
Also practisesINTERNAL MEDICINE
Medical schoolUNIVERSITY OF ILLINOIS COLLEGE OF MED (CHI/PEOR/ROCK/CHM-URB)
Graduated 1986 (40 years in practice)
Group practice Mercy Health System Corporation — 751 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount