House Speaker Paul Ryan on "This Week." ABC ABC anchor George Stephanopoulos grilled House Speaker Paul Ryan on Sunday over the American Health Care Act, which narrowly passed the House of Representatives on Thursday.

In an interview on "This Week," Stephanopoulos asked the speaker why the AHCA, House Republicans' replacement for President Barack Obama's Affordable Care Act, would allow states to opt out of mandating insurers not raise costs for Americans with preexisting conditions.

"Even if you used all $138 billion that you all put in for high-risk pools, that would still cover only a fraction of those with preexisting conditions," Stephanopoulos said.

Ryan defended a provision in the bill that would bar insurers from charging more for people with preexisting conditions as long as they did not lapse in their insurance coverage, adding that "you can't say for healthcare in America one size fits all."

"Under this bill, no matter what, you cannot be denied coverage if you have a preexisting condition," Ryan said. "And under this bill, you cannot only not be denied coverage, you can't be charged higher."

"But you can charge people more," Stephanopoulos interjected.

"Let me finish my point," Ryan said. "You can't charge people more if they keep continuous coverage. The key of having a continuous-coverage provision is to make sure that people stay covered and they move from one plan to the next if they want to. It's kind of like waiting until your house is on fire to then buy your homeowner's insurance. You want to make sure that people stay covered to keep the cost down."

Stephanopoulos also pressed the speaker to answer critics who have said the bill would unfairly benefit the wealthy by rolling back the taxes on high-income earners that helped fund the Affordable Care Act, the law better known as Obamacare.

The ABC anchor said the AHCA would cut $900 billion in taxes, with the most cuts going to people who earn over $200,000 annually, and about $1 trillion in subsidies for Medicaid.

"Most of the benefits go to millionaires," Stephanopoulos said.

Ryan characterized the bill as "a rescue operation," touting what he said were the benefits of block-granting Medicaid, which would give states a lump sum rather than a per-person amount.

"We're giving states the ability to run their own Medicaid program," Ryan said. "I hardly think that's draconian."

"So you don't think anyone's going to be hurt when you're taking $880 billion out of the system?" Stephanopoulos asked.

"No, I don't, because I think the micromanagement of Medicaid by the federal government — the Medicaid system isn't working," Ryan replied. "Doctors aren't taking Medicaid. Hospitals can't survive with Medicaid alone. So by giving the states the ability to customize their Medicaid population, their program to work for them."

Though Ryan defended the House plan, he acknowledged the Senate version would likely differ significantly.

Several top Republicans senators have voiced skepticism of the House plan, which they say would place too many costs on older, poorer Americans and would burden some states with high healthcare costs. The Senate is expected to draft its healthcare legislation in the coming weeks.

Watch the clips below, via ABC: