The Obama administration said Friday it will stop deporting young illegal immigrants who were brought to the United States as children if they meet certain requirements.

The new policy change will cover people younger than 30 who came to the United States before the age of 16, pose no criminal or security threat, and were successful students or served in the military, the Department of Homeland Security said.

It also will allow those meeting the requirements to apply for work permits, the statement said.

What the younger immigrants will obtain, officials said, is the ability to apply for a two-year “deferred action” that effectively removes the threat of deportation for up to two years, with repeated extensions. “This is not immunity, it is not amnesty,” said Janet Napolitano, the homeland security secretary. “It is an exercise of discretion.”

Officials estimated that the new policy would cover about 800,000 people.