Our Physicians

Jeffrey VanGelderen, MD

Robert Thill, MD

Additional Providers

Donna Hammond, PPCNP-BC
Education
  • Delta College
  • University of Michigan – Flint
  • Wayne State University
Licensure and Certification
  • Michigan Registered Nurse
  • Michigan Nurse Practitioner Specialty
  • American Nurses Credentialing Center

Memberships, Offices, & Committee Appointments
  • American Academy of Nurse Practitioners
  • National Association of Pediatric Nurse Practitioners
  • Sigma Theta Tau International Honor Society of Nursing

Jamie Simon, PA-C
Education
  • Michigan State University
  • Central Michigan University
Licensure and Certification
  • Certified Physician Assistant​
Memberships, Offices, and Committee Appointments
  • American Academy of Physician Assistants

​Oksana Lidke, DNP, CPNP-PC
Education
  • Grand Valley State University
Licensure and Certification
  • Michigan Registered Nurse
  • Certified Pediatric Nurse Practitioner
  • Pediatric Nursing Certification Board
Memberships, Offices, and Committee Appointments
  • Nursing Honor Society Sigma Theta Tau
  • Michigan Council of Nurse Practitioners 
  • Sigma Theta Tau International Honor Society of Nursing

​Liza Zulauf, FNP-BC
Education
  • Saginaw Valley State University
Licensure and Certification
  • Michigan Registered Nurse
  • Michigan Nurse Practitioner Specialty
  • American Nurses Credentialing Center

Care Management & Behavioral Health

Laurisa Cummings, LMSW

Education
  • Saginaw Valley State University
  • Michigan State University
Licensure
Licensed Masters of Social Work

Katie LaFleur, LMSW

Education
  • Central Michigan University
  • Michigan State University
Licensure
Licensed Masters of Social Work

Angela Haas, LMSW, CAADC, CBIS
Education
  • Lake Superior State University
  • Michigan State University
Licensure and Certification
  • Licensed Masters of Social Work
  • Certified Advanced Alcohol and Drug Counselor
  • ​Certified Brain Injury Specialist