WASHINGTON (AP) — Travelers who aren’t REAL ID compliant by the upcoming deadline this week will still be able to fly but should be prepared for extra scrutiny, the head of Homeland Security said Tuesday.

Kristi Noem told a Congressional panel that 81% of travelers already have IDs that comply with the REAL ID requirements. She said security checkpoints will also be accepting passports and tribal identification when the deadline hits Wednesday.

Those who still lack an identification that complies with the REAL ID law “may be diverted to a different line, have an extra step,” Noem said.

“But people will be allowed to fly,” she said. “We will make sure it’s as seamless as possible.”

REAL ID is a federally compliant state-issued license or identification card that Homeland Security says is a more secure form of identification. It was a recommendation by the 9/11 Commission and signed into law in 2005, but implementation has been repeatedly delayed.

This is a developing story. Please check back for updates.