Famed healthcare economist Henry Aaron says that  news stories about UnitedHealthcare’s Affordable Care Act insurance-exchange woes are overwrought and do not presage an ACA collapse. He notes UnitedHealth’s special problems:

• Because UnitedHealth’s main business is employer-sponsored coverage, not individual plans,  it has less expertise in the latter market and so doesn’t offer the lowest-premium plans.
• UnitedHealth has just a small amount of market share compared to Blue Cross/Blue Shield companies.
• When UnitedHealth entered the ACA individual market in 2015, a year later than other insurers, it probably had particularly big start-up costs, enrolled fewer and sicker customers and thus had a particularly high attrition rate.