Lapidus cited Anthem Blue Cross and Blue Shield, which includes Siteman in many of its plans outside the Missouri exchange, but none within the exchange.
"We have had many people say to us, 'I picked Anthem because you guys are always in their products, and I assumed you would be in their exchange products'," Lapidus said. "It's still hard to tell who is in network and who is not."
In a statement, Anthem said its network was based on research involving thousands of consumers and businesses. "What we learned was that people are willing to make trade-offs in order to have access to affordable health care," the company said. "Our provider networks reflect this."