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Important Update Regarding UnitedHealthcare (UHC) Coverage

As of October 1, 2025, Madison Medical Affiliates is considered out-of-network with all UnitedHealthcare insurance plans. This change follows the expiration of the contract between Ascension WI & UHC.

We understand how concerning and frustrating this news may be. UHC covers many of our patients and their families, including our own staff. Please know that this development does not change our commitment to providing you with compassionate, high-quality care.

At this time, patients with UHC may experience higher out-of-pocket costs when receiving care at Madison Medical. We encourage you to:

  • Review your insurance benefits to understand how out-of-network coverage works under your specific plan.
  • Visit UnitedHealthcare’s website or call the customer service number on your insurance card for more information about your options.
  • Reach out to our office with questions - we will do our best to guide you and provide support.

While Ascension WI & UHC may continue discussions, we must move forward under this out-of-network status until further notice. We will keep you updated on any changes as soon as we learn more.

For more information, you can visit the official negotiation pages for each organization:

Thank you for your patience, understanding, and trust in Madison Medical Affiliates. We are grateful for the opportunity to care for you and your family.

Important Update Regarding UnitedHealthcare (UHC) Coverage Learn More
Rachel Oosterbaan

Rachel Oosterbaan, M.D.

Dr. Rachel Oosterbaan attended medical school at Wayne State University in Detroit, and she completed her residency in Internal Medicine at Harvard Medical School during her postdoctoral training. In addition to serving as an attending physician at Northwestern Medicine® Lake Forest Hospital in Lake Forest, Illinois and at Northwestern Memorial Hospital in downtown Chicago over the past 16 years, Dr. Oosterbaan also worked as an assistant professor at Northwestern University’s Feinberg School of Medicine since 2000. Dr. Oosterbaan is board certified in Internal Medicine. Her most recent achievements include being voted by Castle Connolly as a “Top Doctor” in the Chicago metropolitan area, as well as voted by US News Report as a “Best Doctor.”

Office Locations

Seton G18

13133 N. Port Washington Road
Suite G18
Mequon, WI 53097
Appointments: (262)-243-5000

Additional Internal Medicine Physicians

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Get started on the road to healing by scheduling an appointment with our Rachel Oosterbaan, M.D. Call for an appointment or complete our contact form.

Seton Professional Building (262) 243-5000

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