When President Obama made his latest pitch for young people to enroll for health insurance though the Affordable Care Act, he threw out all the buzzwords you’d associate with those crazy kids we all call the “young invincibles.”

He talked about Twitter, Facebook, bartenders, and college radio stations. “Host a happy hour!” he suggested.

But the president made no mention of what policy experts say is the real key to enrolling enough young Americans to make his signature health reform effort economically viable—convincing enough Hispanics to sign up.

As the youngest, fastest growing, and least likely demographic in the United States to be insured—more than 40 percent of Hispanic adults have no health insurance—Hispanics represent a huge opportunity to inject a broad swath of young, healthy adults into the health-care system.

But community activists across the country worry that a combination of cultural barriers, mixed-status families, and the delayed launch of the Spanish-language enrollment tools on HealthCare.gov could hamper their efforts to encourage Hispanics to get coverage. Although the tools were quietly posted over the weekend, the Obama administration will not officially launch the full website until January, when it is hoped last-minute problems will have been dealt with.

“The Spanish website, that’s a biggie for me, because we’re finding that a lot of people would prefer to communicate in Spanish and want bilingual information,” said Frank Rodriguez, executive director of the Latino Health Forum in Austin, Texas. “That needs to be fixed and quickly.”

But above and beyond the website issue, members of Rodriguez’s group have been working for more than two years to prepare for what they knew would be major challenges to Hispanics enrolling for health coverage.

“We knew it would be daunting,” he said, describing a Hispanic community in central Texas that was often misinformed about the law’s benefits, unaware of possible tax credits to make coverage more affordable, and wary of sharing personal information with the federal government, especially financial information if they’d been paid in cash in the past.

“They are the working poor. They are the ones within the 100 to 150 percent of poverty level that will capture the subsidies,” Rodriguez said. “I think there are pretty big hurdles, but a lot is going to depend on folks talking to other folks within their local communities.”

Shirley Borghi of the Hispanic Health Coalition of Georgia described a similar dynamic in her state, along with barriers within mixed-status households, where families with American citizens and undocumented immigrants live together and are reluctant to interact with the federal government.

“We are very cognizant of the fact that it could be an issue,” she said. “We let them know, ‘We’re not here to make your life any more difficult. We have no legal right to ask you that question,’ but we can say, ‘Here are the parameters and the options.’”

Like the Latino Health Forum, Borghi’s group has been working with community partners to inform Hispanics about the law, with native Spanish speakers going into churches, pharmacies, and public transportation to encourage Hispanics to enroll, especially young people, who make up 85 percent of the Hispanic population in the state.

“But this is not just a Hispanic issue,” she said. “It’s a socio-economic issue and an education issue.”

The White House has estimated that it will need at least two younger people to sign up for every three older Americans. Without robust enrollment among the country’s 52 million Hispanics, 47 percent of whom are under 27, the numbers for the Affordable Care Act simply won’t add up.

Emma Sandoe, a spokeswoman for CMS, said Spanish speakers have been able to enroll over the phone since October 1 and that the administration is planning a public campaign in January to drive Hispanics to sign up through the website.

“It’s important to remember that the Affordable Care Act is more than just a website and that people are enrolling now,” Sandoe said. “To date, our call center has taken more than 117,000 Spanish-language calls.”

But even when the federal enrollment tools do become available in Spanish, some state-run exchanges, like the one operated by New York state, will continue to be English-only. More worrisome to advocates, some of the states with the highest Hispanic populations and the highest rate of uninsured in the country have opted out of the Medicaid expansion offered through the Affordable Care Act that could have affected hundreds of thousands of young, low-income Hispanics.

The governors of Georgia, Florida, Texas, and 17 other states have declined the Medicaid expansion, and Rodriguez said Gov. Rick Perry also has made it difficult for federal navigators to operate in the Lone Star State. But Rodriguez said he was taking it all in stride as his group pushes to enroll more Hispanics, no matter the obstacles. “It’s just another thing to deal with.”