The Major League Baseball season is now half over, and some fans are already starting to think about the World Series in October.

October is also a big month for the Obama administration.

That's when millions of Americans can start signing up for new health insurance policies through health exchanges established in each state under the Affordable Care Act.

Polls show most Americans still don't understand how they're supposed to do it. The White House and its state partners are eager to let them know. They're trying to recruit baseball teams and other sports franchises to help.

It worked before.

Back in 2007, the Boston Red Sox won the World Series, sweeping the Colorado Rockies in four games. It's also the year that Massachusetts started requiring nearly all residents to have health insurance — and the Red Sox helped to get the word out about it.

The team let the state set up booths at games to explain the new law to fans, and the Massachusetts Health Connector ran ads during Red Sox broadcasts.

Red Sox fan Amy O'Leary remembers it well. "I think it made sense. People feel like they know the players," she says. "I think that sports teams in general can be messengers of good information to a wide variety of people."

Now that other states are opening health insurance marketplaces, they're trying the same strategy.

"People who care about being healthy, our young adult population, are big watchers of the sports shows, and we know [they] are going to be an important population for us to reach," says Myung Kim, outreach director for Colorado's health insurance exchange.

Colorado is focusing on young people because a lot of them are uninsured. And for the Affordable Care Act to work, they need to buy into the system. Young people who probably won't use much health care are expected to balance out older, sicker people who will.

So the state is running television ads during Rockies baseball games that show people buying a health policy and then celebrating as if they'd just won a sporting event. The voice-over in the ads says, "Connect for Health Colorado, because when health insurance companies compete, there's only one winner: You."

But while Colorado follows Massachusetts' lead on advertising its new insurance marketplace, it is one of only 15 states independently setting up their own exchanges. The federal government is fully or partially at the helm of the insurance exchanges in all the other states.

It could be tough to get through to young people who may not value having health insurance. "We also know that they're most heavily marketed to, so it's really hard to break through to this group," says Mandy Cohen, with the federal Department of Health and Human Services. "We know we had to put an extra emphasis on the 18- to 35-year-old cohort."

But when the White House reached out to pro baseball, NASCAR and other sports organizations to discuss marketing partnerships, some Republicans called a foul. The National Football League reportedly passed on the idea of helping to market the exchanges.

Senate Minority Leader Mitch McConnell, R-Ky., sent the sports leagues a letter saying they, "risk damaging [their] inclusive and apolitical brand[s]" by promoting the federal health care law.

That didn't happen in Boston. "We didn't have negative feedback," says Charles Steinberg, a Red Sox executive. "In American democracy we debate issues and we come to resolution and we pass laws. And those laws are designed to benefit the people. So when you can be a communicator of the laws of the land, you believe that you're helping people."

Still, the White House as of now has canceled at least some of its meetings with sports leagues about potential partnerships.

In Colorado, the ads running during Rockies TV broadcasts haven't stirred up any controversy. But they might not be home runs either.

The same night O'Leary was in Boston, Joan Ringel was at the Rockies game. She's seen the ads on TV and says it's hard to even tell what they are for.

"You wouldn't know that that is Colorado's exchange for the Affordable [Care] Act," Ringel says. "I didn't think they explained clearly that people need to pay attention to the exchange when it's time to sign up."

This piece is part of a collaboration among NPR, Colorado Public Radio and Kaiser Health News.

Copyright 2013 CPR News