WASHINGTON – With Democrats already annoyed at the insurance industry over its opposition to health care legislation, a House subcommittee heard Thursday from a Garland father and others about the perils of confusing policies that left them with uninsured catastrophes.

David Null, who owns a Garland air-conditioning system cleaning business, was forced into Medicaid in 2005 for two years to cover $600,000 in medical bills after a liver transplant for his 7-year-old daughter, Tatum.

Null said he had bought a health insurance policy that he thought gave his family catastrophic coverage but learned in the hospital that it maxed out at $25,000.

The hearing focused on the estimated 25 million Americans who are "underinsured," or who lack coverage sufficient for unexpected and costly medical emergencies.

Sara Collins, a vice president with the New York-based Commonwealth Fund, told the subcommittee that 9 million more Americans fell into the underinsured category between 2003 and 2007 because of rapidly increasing costs for insurance and medical care.

Much of the discussion at Thursday's hearing dealt with deceptive sales practices that left consumers unaware of the inadequacies of their health insurance policies.

A San Francisco film producer testified that the policy she bought left her with $100,000 in bills after a five-year battle with breast cancer.

A Colorado engineer said his son's hemophilia caused his employer's health insurance premiums to jump to $22,000 per employee and forced him to leave the firm after hitting a $1 million lifetime cap on treatment.

"We were the bomb that went off. They [the other employees] were the casualties all around us," said Nathan Wilkes of Englewood, Colo.

Democrats and Republicans on the House panel sparred over the merits of legislation that overhauls the health insurance industry, which the committee approved in July.

But there was little sympathy in the hearing for the insurance industry.

Rep. Joe Barton, R-Arlington, said he hoped the committee would reach a consensus "to cure the disingenuity of private insurance practices."

Rep. Henry Waxman, D-Calif., who chairs the Energy and Commerce Committee, said the testimony pointed up "a lot of the schemes insurance companies have not to pay."

The subcommittee invited the Nulls to testify after their situation was described in a Sept. 20 article in The Dallas Morning News. David and Tatum Null used the opportunity to vent their concerns with health insurance practices.

"I asked in very plain language for an 'Oh, no!' policy, but we ended up with no such thing," Null said.

He told the committee that, under the current insurance market, Tatum would never be able to pursue a career choice as an independent businesswoman because she would be "blacklisted" from getting health insurance on her own because of a pre-existing conditon.

"I can't tell her she can grow up to do anything she wants, and you guys need to fix that for me," Null told the subcommittee.

Tatum, now 12, said:

"I do want to live my American dream, and I hope the committee can do that for me."

Waxman assured Tatum that, under the Democrats' health insurance overhaul legislation, "your future will not be hindered."

No one from the insurance industry participated in the hearing. Industry representatives have said insurers back changes that would clarify policies and stop the practice of barring insurance for individuals with pre-existing conditions, but only if the congressional proposals extend coverage to all Americans.

The Census Bureau estimates 46.3 million people lacked health insurance last year.

The insurance industry this week launched an advertising campaign against the overhaul bills heading for a vote in the House and Senate. The industry is warning seniors that the legislation would eliminate benefits from Medicare Advantage plans, cut Medicare spending and raise insurance premiums for families by another $4,000 a year.

Democrats in Congress and the White House have rejected those arguments and say the industry is trying to defeat reforms that would require them to insure all Americans regardless of pre-existing medical conditions and clarify misleading policies.