what is incurred but not reported ibnr 
incurred but not reported ibnr is a type of reserve account used in the insurance industry as the provision for claims and or events that have transpired but have not yet been reported to an insurance company in ibnr situations an actuary will estimate potential damages and the insurance company may decide to set up reserves to allocate funds for the expected losses to an actuary these types of events and losses are said to have been incurred but not reported 