Nearly a quarter of all people who bought Obamacare health plans still cannot afford the care they need, a leading advocate for President Obama’s healthcare law says.

Families USA, a group that often proposes improvements to the law, says high deductibles make healthcare unaffordable for many people, even though they now have insurance.

A survey released by the group Thursday found that nearly one in four adults shopping in the new insurance marketplaces bought plans with deductibles of $3,000 or more and 42 percent enrolled in plans with at least a $1,500 deductible.

It means many customers are forgoing needed health services because they cannot foot the bill.

“They could not afford tests or they could not afford various treatments or they could not afford the cost of medicines,” said Families USA President Ron Pollack. “The key culprit [is] high deductibles.”