The result is a communications void that civic and political groups, mayors, insurers and hospitals will try to fill.
"You have people who aren't really charged up about it because they don't even know that they would qualify," said Durrel Douglas, spokesman for the Texas Organizing Project, an activist group. A national poll this week by the nonpartisan Kaiser Family Foundation found that two of every three uninsured people don't know enough about the law to understand how it will affect them.
Supporters of Obama's law in Texas say the federal government hasn't shown up yet to launch the state's insurance exchange and no one is sure when that will happen.
"It is a much bigger lift here," said Anne Dunkelberg, associate director of the Austin-based Center for Public Policy Priorities, which advocates for low-income people. "The sooner the federal exchange can get engaged and working with all the folks here who want to promote enrollment, the better."
The Congressional Budget Office predicts a slow start overall, with only 7 million gaining coverage through the exchanges next year, rising to 24 million in 2016.
At a recent insurance industry meeting, federal officials directing the rollout rattled off a dizzying list of deadlines. Public outreach will begin in earnest this summer and early fall, said Gary Cohen, head of the Center for Consumer Information and Insurance Oversight.
The government sees three main groups of potential customers for the new insurance markets, he said.
There's the "active sick and worried," people who are uninsured or have pre-existing medical conditions. Under the law, insurers will no longer be able to turn the sick away.
There's the healthy and young. "They feel invincible, they don't feel a need for health insurance," said Cohen.
Finally, there's the passive and unengaged. "For these people, a significant education effort needs to happen," he said.
To keep premiums affordable, the government will need to sign up lots of people from the last two groups to balance those in poor health, who will have a strong motivation to join.
The official heading consumer outreach for the rollout, Julie Bataille, acknowledges the challenge but says she's confident.
"This is a really an enormous opportunity for us to change the conversation around health care and help individuals understand the benefits they can get," she said.