The official cut-off for claims processing is generally on the 18th of each month at 5:00 EST but may occur on varying days due to holidays or other factors (December is usually around the 13th). 

Claims will continue to be processed by OHIP during the rest of the month but are not guaranteed to be processed after the official cut-off date. If a claim is not submitted by official cut-off it may not be assessed until the next monthly billing cycle.