DES MOINES, Iowa (AP) — A state official on Tuesday reiterated that Iowa's individual health insurance market under the Affordable Care Act will collapse if the federal government doesn't approve a short-term funding proposal aimed at stabilizing premium costs.

Iowa Insurance Commissioner Doug Ommen told reporters the state has communicated with the Centers for Medicare and Medicaid Services for months to finalize details of the so-called stopgap measure. The state submitted its final version of the measure Monday.

"We now view that this may be the only option that we have to stabilize the market," Ommen said.

The stopgap measure redirects federal ACA money in order to help people priced out of subsidies that currently help pay for some coverage in the individual market. Ommen said he recognizes "valid" concerns the proposal could raise costs for some people whose increasing health insurance costs were previously capped, or raise how much people pay in deductibles.

Ommen said given the possibility that thousands of people would go uninsured in 2018, "you can't take out of a market hundreds of millions of dollars in premiums from healthy people and expect it to look even better next year. It won't."

About 72,000 Iowans have individual ACA-compliant health plans, according to state officials. Ommen used an actuarial study to estimate between 18,000 and 22,000 of them will drop coverage next year if no action is taken to offset growing premium costs.

Minnesota-based Medica, the last carrier to offer statewide plans in Iowa's individual market, announced this month that increases to premium rates could be up to 56.7 percent. The company said uncertainty from the federal government led to the additional premium hikes.

The 192-page proposal, submitted to the U.S. Department of Health and Human Services and the U.S. Department of Treasury, has letters of support from Iowa Republican leaders. That includes Gov. Kim Reynolds, Sens. Charles Grassley and Joni Ernst and Iowa's three Republican U.S. House members. All of them have pointed to Iowa's insurance market as proof the federal health care law passed under President Barack Obama is not working. The future of the law remains unclear after the GOP-led Congress failed to enact legislation this summer that would repeal and replace it.

It's also unclear when the federal government will respond to the proposal. State officials hope for quick action, as they prepare for a health insurance enrollment period that begins Nov. 1.