WASHINGTON — Lawmakers and health-care witnesses at a House Ways and Means subcommittee hearing on care coordination urged Congress to extend the enhanced Affordable Care Act premium tax credits, warning that tens of millions of Americans face sharp premium increases and coverage loss next year.

Brian Connell, vice president of federal affairs at Blood Cancer United, told the panel that the lapse of enhanced premium tax credits would make coverage unaffordable for many and urged lawmakers to "Extend the current premium tax credits." Connell cited examples of consumers who would see monthly costs rise by hundreds or more and said a replacement relying on health savings accounts would not protect people with high-cost conditions.

"If we scrap that system and we replace it with one that forces patients to buy plans with higher deductibles ... we're just shifting more costs to the consumers," Connell said. He warned that patients who cannot afford care would defer treatment, rack up medical bills and in some cases die from untreated conditions.

Several lawmakers pressed witnesses on the scale of the risk. Members repeatedly returned to the same point: coverage is a prerequisite for effective care coordination. Representative Chu said the committee cannot discuss modernizing coordination if people do not have insurance, adding that the question of premium tax-credit expiration is "the crisis we are facing today." Witnesses and members noted that some estimates showed millions of people could face premium spikes.

Witness testimony underscored the stakes for people with chronic and high-cost conditions. Connell said the first-year cost of care for some blood cancer patients can range into the hundreds of thousands of dollars, and that such care is "unconscionable" to pay out of pocket. Committee members said the prospect of higher Medicare Part B premiums and flat Social Security cost-of-living adjustments adds pressure on seniors.

The hearing included discussion of alternatives. Witnesses cautioned that health savings accounts (HSAs) cannot function as a substitute for exchange subsidies because HSAs cannot pay monthly premiums and are frequently paired with high-deductible plans, leaving patients with large out-of-pocket exposure.

The hearing ended without formal action. Members were reminded they have two weeks to submit written questions. The committee did not vote on legislation during the proceeding.