What does “Plan Check Expired” mean on a building permit?

Your LADBS plan check ran out of time. The 18-month plan check period — which starts at 'Submitted' — has elapsed before the plans were approved. The application is not dead, but it cannot proceed until the plan check period is extended by a supervisor.

What should you do when a permit shows “Plan Check Expired”?

Request a supervisor extension to reactivate the plan check (LADBS shows this as 'PC Extended' once granted). Plan ahead on complex projects so you do not hit the 18-month wall mid-review. Note this is distinct from 'PC Approved' or a permit-stage 'Expired' — this is the review window lapsing, not the issued permit lapsing.