Byron York, back in 2011, here:
Dunham unquestionably had health coverage. "Ann's compensation for her job in Jakarta had included health insurance, which covered most of the costs of her medical treatment," [Janny] Scott writes. "Once she was back in Hawaii, the hospital billed her insurance company directly, leaving Ann to pay only the deductible and any uncovered expenses, which, she said, came to several hundred dollars a month." ... the story Obama told, Scott writes, was "abbreviated" -- the abbreviation was to leave out the fact that Ann Dunham had health insurance that paid for her treatment. "Though he often suggested that she was denied health coverage because of a pre-existing condition," Scott writes, "it appears from her correspondence that she was only denied disability coverage."