DES MOINES, Iowa — Iowa’s state insurance division says residents in 13 rural counties who want to buy subsidized health insurance under the Affordable Care Act will have just one provide to choose from for 2017.

Medica, a Minnesota-based carrier, is the only health insurer that has agreed to sell individual policies throughout the state via the Affordable Care Act’s online marketplace. The Obamacare marketplace was touted as a way to encourage competition among health insurers.

The Des Moines Register ( ) reports that about 55,000 Iowa residents bought individual health insurance policies for 2016 on the marketplace, and most had incomes low enough to qualify for subsidies, which come as tax credits. The marketplace is designed for people who buy their own policies instead of obtaining them via an employer or government program.

Counties that will only have Medica as an option include Adams, Buena Vista, Iowa, Jefferson, Keokuk, Lee, Louisa, Mahaska, Page, Pocahontas, Taylor, Van Buren and Wapello. The insurance division reported that residents of some urban counties will have access to policies from Aetna, Medica and Wellmark.

Insurance Commissioner Nick Gerhart urged customers to shop around for coverage, if possible.

“It’s important for Iowans to be sure they look at all factors, such as cost … whether their preferred doctor is within that plan’s network; and the types of coverage and services offered under the different plans,” Gerhart wrote in a press release.

The market for individual policies has been hit by bigger increases in premiums than the market for employer-provided health coverage. Gerhart recently approved rate increases of 19 percent to 43 percent for more than 75,000 Iowans who buy their own policies. The insurers successfully argued that they needed the increases to cover the unexpectedly high healthcare costs of previously uninsured Iowans.

Information from: The Des Moines Register,