Healthcare.gov website homepage on Jan. 8th, 2014. Adam Jeffery | CNBC

A .430 batting average will guarantee you a spot in the Baseball Hall of Fame. In Obamacare's Hall of Fame, however? Not so much. A new survey finds that 51 percent of people who used the government-run Obamacare health insurance exchanges in the past year say they will not to do so again when open enrollment resumes Nov. 15. Read MoreEnding Obamcare subsidies: Risks vs. rewards

Just 43 percent of people who used HealthCare.gov, the federal insurance marketplace, or a state-run exchange plan on using such an exchange to shop for 2015 insurance plans, the Bankrate.com survey found.

"I do think the results should be of concern for the [Obama] administration," said Bankrate insurance analyst Doug Whiteman. "It didn't win over a lot of loyal or happy customers," Whiteman said. "These people are just kind of shrugging their shoulders when it comes to the open-enrollment seasons that's coming," adding that the results were "lop-sided." However, Whiteman noted that some of the respondents who said they didn't plan on using the Obamacare exchanges "might just let their policy auto-renew," without shopping for a new plan on those online marketplaces.

"We're telling people they shouldn't do that. They should explore any options they might have," Whiteman said. "That is a concern if people are just planning on auto-enrolling the plans they have because that might be a mistake." Read MoreMedicare agency focus of insider trading probes

Bankrate's advice mirrors that of the federal government, which has urged current Obamacare customers to select the plan that best suits their financial and health needs. The Bankrate survey questioned 588 people over the past month who had used the exchanges. That pool includes people who ended up selecting an insurance plan, and those who did not. The survey has a margin of error of plus or minus 4.7 percentage points.