The study sought to break out the experience by new enrollees and by those enrolling for a second time. For this rating, J.D. Power asked respondents about the amount of time to complete the renewal/enrollment process; clarity of instructions for completing enrollment application; courtesy of the representative; ease of navigating the exchange website; ease of renewing/enrolling; ease of understanding benefits and coverage; and variety of information available about health insurance plan choices.

The study looked at experiences with three exchange models: federally operated exchanges, state-operated exchanges, and state-federal partnership exchanges (operated jointly by the feds and a state). Scores are based on a possible 1,000 points.

Among the major findings:

• Enrollment satisfaction among new enrollees has increased by a significant 55 points to 670 from 615 in 2014;

• Satisfaction with the re-enrollment process is higher among those who auto re-enrolled (744) than among those who did not (724);

• Among re-enrollees, satisfaction was the highest among those who enrolled through the federally facilitated marketplace (739);

• The partnership marketplaces received the second highest satisfaction rating (730);

• State-based marketplaces finished third (713);

• Among new enrollees, satisfaction is highest among those who enrolled through a partnership marketplace (680), followed by the federally facilitated marketplace (669) and state-based marketplaces (668).

• 78 percent of re-enrollees kept their plan, usually citing satisfaction with their premiums, while 22 percent switched plans primarily due to cost concerns such as monthly premiums;

• Re-enrollees primarily use online research while shopping, particularly health plan websites (58 percent), followed by general online search (51 percent) and online consumer reviews (29 percent).

When asked about their overall satisfaction with their exchange health plan, here's the feedback:

• Overall satisfaction with the exchanges health plan experience is 696;

• Marketplace plan satisfaction is highest in states with a partnership marketplace (716), followed by the federally facilitated marketplace (699) and state marketplaces (683).

• Among the 11 states oversampled in the study, satisfaction is highest for plans in Pennsylvania (752), Illinois (746) and Georgia (745);

• California is the only state in which satisfaction with non-marketplace exchange plans (695) is higher than with marketplace exchange plans (656).

• Across exchange types, plan members are most satisfied with the provider selection and claims processing attributes.

"Marketplace shoppers are very cost-sensitive," said Rick Johnson, senior director of the health care practice at J.D. Power. "Unlike many traditional health plan members, who are often tied to a single employer benefit offering, Marketplace members have an option to switch plans annually, allowing them to shop for either the most affordable or the most valuable plan. Plan providers need to demonstrate the value of their plan by clearly communicating coverage and benefits. Additionally, auto re-enrollment is a great way to both ease the re-enrollment process and increase member retention."