Essential versus nonessential. For millions of federal workers, it’s a critical distinction, and one that agency inspectors general are likely to take a close look at once the government shutdown ends.

“There’s a lack of clarity about who constitutes an essential employee and who is not,” said H. David Kotz, inspector general of the U.S. Securities and Exchange Commission from 2007 to 2012 and now a director at the Berkeley Research Group.