Florida continues to be a hotbed of Affordable Care Act activity and an attraction for insurers specializing in government-sponsored plans. Florida's federally facilitated health insurance exchange has been boasting the highest enrollment in the nation. Health plans have been developing new partnerships, such as accountable care organizations, narrow networks with independent physician organizations, and integrated delivery networks, opening the door for tighter insurer-provider collaboration. Meanwhile, the merger between Centene Corp. and WellCare Health Plans Inc. consolidated the state's largest Medicaid MCOs and gave Centene a significant Medicare Advantage carrier. A push for Medicaid expansion is stalled, however. Meanwhile, Medicare Advantage plans continue to see their popularity increasing in the state.