SIOUX FALLS, S.D. — A Dakotas nonprofit is urging people who buy their own health insurance to sign up early during the Affordable Care Act open enrollment period that started Wednesday.

The enrollment window for 2018 health coverage through the federal marketplace runs until Dec. 15. This year’s sign-up period is six weeks shorter than last year’s.

Community HealthCare Association of the Dakotas CEO Shelly Ten Napel said in a statement that community health centers and their health care partners are working to inform people that coverage and financial help are available.

She said people who plan to renew or enroll in a health plan should get prepared and sign up early to ensure coverage. Counselors and navigators are ready to help people sign up, Ten Napel said.

“With a shortened enrollment period and steep cuts at the federal level for marketing and outreach efforts, it is critical that we spread the word about open enrollment and arm South Dakotans with the information they need to enroll, apply for financial assistance and seek enrollment support,” she said.

The nonpartisan Kaiser Family Foundation said that for the 2017 open enrollment period, over 21,000 people in North Dakota and more than 29,000 people in South Dakota selected a marketplace plan.