The Commonwealth Fund Health Insurance Tracking Survey of U.S. Adults indicated 57 percent were uninsured for two years and more, while 69 percent were without coverage for a year or longer.
Of the group who lost health insurance:
-- 62 percent of those who tried to buy a policy in the past three years said it was very difficult or impossible to find affordable coverage.
-- 31 percent were turned down, charged a higher price or had a condition excluded because of a pre-existing condition.
-- 45 percent said they had never bought a healthcare plan mainly because of cost.
Study authors Sara R. Collins, Ruth Robertson, Tracy Garber and Michelle M. Doty said, compared with U.S. adults who had continuous health insurance coverage, those who experienced gaps were less likely to have a regular doctor and less likely to be up to date with recommended preventive care tests, with rates declining as the length of the coverage gap increases.
However, early provisions of the Affordable Care Act were helping bridge gaps in coverage among young adults and people with pre-existing conditions, the researchers said.