PORTLAND, Ore. (AP) — With federal and state online health care marketplaces experiencing glitches a month into implementation, concern is mounting for a vulnerable group of people who were supposed to be among the health law's earliest beneficiaries.

Hundreds of thousands of people across the country with pre-existing chronic conditions who are covered through high risk-insurance pools will see their coverage dissolve by year's end.

The Affordable Care Act will allow them to gain regular coverage. But many have had trouble signing up through the exchanges and could find themselves without insurance in January if they don't meet a Dec. 15 enrollment deadline.

More than a dozen of the 35 state-run pools and the federal pools are set to close within a month and a half.

Administration officials say the federal exchange won't be working probably until the end of November.