LOS ANGELES (AP) — About 100,000 Californians who haven’t yet proved their citizenship or legal residency in the U.S. face losing their health care coverage this fall, state officials said.

The state will start sending notices to affected consumers early next month and follow up with more communication, the Los Angeles Times reported Friday.

Covered California, the state-run insurance exchange, enrolled more than 1.2 million people during the rollout of the Affordable Care Act this year. The exchange said it could verify citizenship or immigration status of most consumers electronically through a federal data hub.

But Peter Lee, the exchange’s executive director, told the Times that about 100,000 people must still submit proof of eligibility or risk losing coverage in October.