Hundreds of thousands of people who signed up under the new health care law risk losing their taxpayer-subsidized insurance unless they act quickly to resolve questions about their citizenship or immigration status. The government is warning that they have until Sept. 5 to show that they’re eligible.

Of the 8 million people who signed up for private coverage through President Barack Obama’s law, more than 2 million at one point had discrepancies of one sort or another that could have affected their eligibility. That number has been greatly reduced — but the remaining cases are proving difficult to untangle.

Officials at the Health and Human Services Department said that letters are being sent to about 310,000 people with citizenship or immigration issues, many of whom haven’t responded to previous outreach efforts.

Only a few months ago, in May, there were nearly 970,000 people with such problems. But most of those cases were cleared up, or are now being resolved.

The letters will notify the remaining consumers that the still need to upload their documents to HealthCare.gov, or mail them in. Otherwise, their coverage will end on Sept. 30.

The letters are being sent in English and Spanish.

The new policy affects the 36 states where the federal government has taken the lead in running online insurance markets created by the law. It’s unclear how it will apply in places like California and New York, which are running their own insurance exchanges.

Consumers who have unresolved discrepancies over their incomes will get notices at a later date.

The new health law provides subsidized coverage to people with no access to health insurance on the job. More than 80 percent of those signed up are getting subsidies to help with their premiums and, in some cases, their copays and deductibles as well.

But those taxpayer subsidies are contingent on meeting a host of requirements. Illegal immigrants are not allowed to get coverage. And the amount of a consumer’s premium tax credit can vary by income, family size, hometown and other factors. That can make getting covered through the law feel somewhat like doing your taxes.

The letters that started going out Tuesday won’t be the final attempt to reach those with unresolved issues. HHS will try to contact each consumer two more times by phone and once via email. The administration is also working with local organizations to try to reach people directly in their homes.

(AP)