Some 13 million uninsured young adults 19 to 29 could gain health insurance coverage if reforms in Congress are approved, a U.S. non-profit group says.

A Commonwealth Fund report, "Rite of Passage? Why Young Adults Become Uninsured and How New Policies Can Help," said young adults often become uninsured when they graduate from high school or college; are dropped from their parents' policies or become ineligible for Medicaid or the State Children's Health Insurance Program; have difficulty becoming employed or work part-time.

Young adults comprise 17 percent of the under-65 population, but represent nearly 30 percent of all uninsured Americans, the report said.

Some of the current proposals would allow young adults to remain on their parents' health plans until they are age 26. Young adults in lower-income households, who represent nearly 70 percent of all uninsured young adults, would be eligible for Medicaid or sliding scale premium subsidies or a health insurance exchange.