SIOUX FALLS, S.D. (AP) — About 300 South Dakota residents who bought insurance through the Affordable Care Act marketplace could lose their coverage if they don't submit citizenship and immigration documents to confirm their eligibility.

Consumers have until Sept. 5 to provide the paperwork or their coverage will be canceled on Sept. 30.

People living in the country illegally aren't allowed to get coverage. The federal government this week sent letters to those who still haven't submitted their documents to warn them of the deadlines.

Officials say the letters tell consumers that they can upload their documents to HealthCare.gov or mail them in.

Nationwide, letters were sent to more than 310,000 people whose citizenship or immigration details don't match what the government has on file. Officials say most people haven't responded to previous outreach efforts.

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