UnitedHealth Group, the nation’s largest private insurer, next year plans to exit most of the 34 states where it offers plans in the Affordable Care Act’s Health Insurance Marketplaces, the company announced today. “The smaller overall market size and shorter term, higher risk profile within this market segment continue to suggest we cannot broadly serve it on an effective and sustained basis,” said United HealthGroup CEO Stephen Hemsley. “Next year, we will remain in only a handful of states, and we will not carry financial exposure from exchanges into 2017.” If UnitedHealth were to exit from all 1,855 counties where it currently participates in the Marketplaces, 29% of the counties would be left with just one Marketplace insurer and another 29% would be left with two, according to an analysis released yesterday by Kaiser Family Foundation. “In areas with limited insurer participation, the remaining plans after a United exit may have more market power relative to providers, but in the absence of insurer competition, those savings may not be passed along to consumers,” the authors said.