Early data shows Obamacare needs more younger enrollees to work

Now that more than 2 million people have signed up for private insurance plans created by US President Barack Obama's health care law, a crucial next check-up for the new marketplace will be to see how old customers are.

Early data from a handful of state exchanges shows the administration needs more young adults to sign up in the next three months to help offset costs from older enrollees and prevent insurers from raising their rates.

Critics of Obama's Affordable Care Act say the market won't attract enough young people to keep it financially viable, putting more pressure on government funds to compensate for any insurer losses.

Data from seven states and the District of Columbia, which are running their own marketplaces, show that of more than 200,000 enrollees, nearly 22 per cent are 18 to 34 years old.

The administration had hoped that more than 38 per cent, or 2.7 million, of all enrollees this year would be 18 to 35 years old, based on a Congressional Budget Office estimate that 7 million people would sign up by the end of March.

"The whole insurance relationship is counting on them signing up," said Dale Yamamoto, an independent health care actuarial consultant. "Otherwise rates will have to increase."