The newly appointed CEO of HealthCare.gov is predicting fresh challenges for the system's second enrollment period this November.
Kevin Counihan, former head of Connecticut's exchange, cited concerns such as the shorter sign-up period for 2015 plans that could create problems for officials and consumers alike.
The comment highlights the heady task facing federal health officials as they work to prevent a repeat of last year's first enrollment period.
Last year, technical flaws at HealthCare.gov and other exchanges plunged the enrollment process into chaos and created an enormous political headache for the Obama administration.
Counihan did not indicate that his fears related to the technology, which has undergone extensive repairs since last October.
The 2014 sign-up period was six months long, but with just three months to enroll more consumers, this year's process could prove a tough climb as insurers and the government seek to convince hard-to-reach populations to buy health plans.
Existing policyholders are likely to encounter changes in their premium prices that could also cause confusion.