According to a recent report, here is what adults who either ...

... had enrolled in private health plans through the marketplace for the first time, or had switched plans, said was the most important factor in choosing a health plan:

• the amount of the premium (36%)
• the amount of the deductible and copays (26%)
• the inclusion of their preferred doctors and hospitals in their plan’s network (28%)

Source: "New ACA Marketplace Findings: Subsidies For Lower-Income Enrollees Make Insurance Premium And Deductible Costs Comparable To Employer Coverage," The Commonwealth Fund, July 7, 2016, http://www.commonwealthfund.org/publications/press-releases/2016/jul/new-aca-marketplace-findings-coverage-and-affordability