Now available on our website is a new resource dedicated to provider-specific information for Keystone HMO Proactive. This new web page explains the criteria used for benefit tier placement, gives an overview of the Health Insurance Marketplace, and answers some frequently asked questions about Keystone HMO Proactive. >> Keystone HMO Proactive Note: The Keystone HMO Proactive web page is located within the Tools and Resources section of ibx.com/providers.