Pennsylvania Insurance Commissioner Teresa Miller said Thursday that five health insurers submitted rate requests with average statewide increases of 8.8 percent for the individual market and 6.6 percent for small-group plans, but warned that the rates could skyrocket if Congress and the Trump administration make significant changes to the Affordable Care Act.

"These low percentages show that Pennsylvania's market is stabilizing and insurers are better understanding the markets and the population they serve," Miller said.

A year ago, insurers requested average increases of 23 percent and were ultimately approved for average increases of 32.5 percent, after it became clear that insurers were facing steep losses on the 2016 rates, Miller said.

Insurers submitted their rate filings for 2018 health insurance plans on May 22. Details on the rates, which vary by region, will be available on July 21 at, Miller said.

At this point, all 67 Pennsylvania counties will have at least one insurer selling plans on the ACA exchange, making them eligible for subsidies. About 16 or 17 counties, including the five-county Southeastern Pennsylvania, are expected to have just one company on the exchange. More than a half-million Pennsylvanians have ACA-compliant plans that were purchased in the individual market.

If Congress repeals the individual mandate, insurers estimated that they would seek a 23.3 percent rate increase statewide. If cost-sharing reductions are not paid to insurers, the companies would request a 20.3 percent rate increase statewide. Insurers estimated they would seek an increase of 36.3 percent if both changes occurred, Miller said.

The five insurers that submitted requests are affiliates of Independence Blue Cross, Capital Blue Cross, Geisinger Health Plan, Highmark, and UPMC.