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Mercy Clinic Internal Medicine - Medical Tower A Suite 189

Doctor's Office
621 S. New Ballas Road, Tower A, Suite 189-A
St. Louis, MO 63141

Main Entrance: Medical Tower A - Free valet available


Phone: (314) 251-6335
Fax: (314) 251-5864
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You don’t often think about your doctor until you get sick. At Mercy Clinic Internal Medicine - Medical Tower A in St. Louis, MO, we want to change that. Being well between visits is just as important. Our internal medicine doctors focus on education and answering your health care questions and concerns, enabling you to take an active part in your health care. And our team is also linked to numerous medical specialists and a full range of diagnostic laboratory and imaging services when you need them.

Mercy's internal medicine doctors are connected by our advanced electronic health record system, so your most up-to-date medical information is instantly available to the caregivers at each point of medical care.  In addition, you can take advantage of MyMercy, an online service to view test results, make appointments, and send secure messages to your doctor and more –anytime and anywhere.

Please note: Carolyn Lewis Koenig, MD is now only accepting Medicare and Medicare Advantage insurance. 

We've made it easier to reach us.

Our new, extended phone hours: 
M-F | 7 a.m. - 7 p.m.
Sat | 8 a.m. - noon

While our care team is still available to answer your medical concerns 24/7, we're extending our phone hours for non-medical needs, too. Call to schedule an appointment, request refills and more during our extended phone hours. Or use your MyMercy app or mercy.net anytime.

Meet Our Team