The U.S. Department of Health and Human Services (HHS) reported this week that premiums on midlevel health plans offered through the Affordable Care Act (ACA) will increase by an average of 25% next year. This comes as HealthCare.gov prepares to open 2017 enrollment on November 1, and Election Day takes place one week later. Both Hillary Clinton and Donald Trump have promised to make alterations to the law in an effort to counter rising prices and narrowing options.

HHS also reported that consumers in some states will have fewer insurance companies to choose from within the public marketplace. The Obama administration says that, with federal subsidies in the form of tax credits, 75% of customers will find plans for less than $100 a month, and also announced last week that it expects 11.4 million monthly enrollees on average in 2017, up from 10.5 million in 2016.

Kevin Griffis, a spokesman for HHS, says the number of people eligible for tax credits will increase as premiums go up next year. Officials also stated that consumers could lower their costs by choosing less expensive plans for next year while taking advantage of the subsidies for which they’re eligible. Currently, plans are classified into platinum, gold, silver and bronze coverage levels.

The average 25% increase follows a more modest 7% increase in premiums at the same time last year, and a 2% increase two years ago.

In recent months, major healthcare insurance companies have stated they will pull out of the public marketplace, citing multimillion-dollar losses. Aetna announced in August that it would sell individual policies in only 242 counties in four states in 2017, down from 778 counties in 15 states this year. The company referred to a shortfall of $430 million on Obamacare plans in the first half of 2016. This followed similar announcements by UnitedHealth Group in April, and Humana in July. For those insurers choosing to remain in the Obamacare marketplace, state officials have approved rate increases of 25% to 50% or more as the companies struggle to cover their costs.

“There will be a lot of upheaval for consumers this open enrollment period, with premiums increasing substantially in many parts of the country and fewer insurers participating,” Larry Levitt, senior vice president at the Kaiser Family Foundation, told USA Today. “Whether this is a one-time market correction or a sign of more problems ahead will depend in large part on how consumers react to the changes.”

Among the 38 states that rely on the federal exchange, as opposed to those that oversee their own ACA marketplaces, the average number of plans available to residents will decline by more than a third, from 47 to 30, though the change varies widely from state to state. In Florida, for example, customers will have an additional three plan choices on average, while Arizonans will now have only four plan choices, down from 65 this year. In 2016, 2% of all exchange customers found just one company for possible coverage. That number will skyrocket next year to 21%.