About 1,200 immigrants in Maine will soon receive a letter asking them to provide documentation proving they are legally in the United States or risk losing health insurance through the Affordable Care Act.

Immigrants who are legally in Maine were permitted to purchase subsidized health insurance on the federal marketplace, where the uninsured – often part-time or self-employed workers – can shop for benefits. Subsidies that greatly reduce the cost of a health plan are available to people who make between 100 percent and 400 percent of the federal poverty limit, or up to about $47,000 for an individual.

Officials with the U.S. Centers for Medicare and Medicaid Services, the agency sending the letters, emphasized that immigrants will not lose their health coverage as long as they provide proof of their legal standing by Sept. 5. Those who fail to do so will see their coverage end by Sept. 30.

But Robyn Merrill, a senior policy analyst at Maine Equal Justice Partners, said it may be difficult for some immigrants to meet the deadline. The letters went out in English and Spanish, but in Maine, many of the immigrants are from African countries and speak Somali or French.

In some cases, government officials have lost applicants’ paperwork.

“Many individuals sent in the documentation, but it was misfiled. There’s been lots of glitches and systemic problems,” Merrill said. Maine Equal Justice Partners has been working with the advocacy group Consumers for Affordable Health Care to help immigrants sign up for marketplace benefits.

Merrill said immigrants also had problems signing up for insurance, because often the immigrant status was causing glitches with healthcare.gov, the website that most people used to sign up for benefits.

Nationally, more than 450,000 cases with documentation issues have been resolved, and 310,000 people will receive letters requesting verification, according to a CMS news release. There is no estimate of how many Maine-based immigrants have already satisfied the federal government by providing the proper documents.

“We want as many consumers as possible to remain enrolled in marketplace coverage, so we are giving these individuals a last chance to submit their documents before their coverage through the marketplace will end,” CMS Administrator Marilyn Tavenner said in a statement.

Customers can call 1-800-318-2596 or log onto their healthcare.gov account to determine what documents are needed. Or those seeking help can call Consumers for Affordable Health Care at 1-800-965-7476.