Definitions for "IBNR"
Incurred But Not Received
Incurred but not reported. An insurer's estimate of costs associated with claims that have not yet been submitted for payment, based on studies of prior lags in claim submissions. Used to set claim reserves.
Incurred But Not Reported. The actuarial estimate of reserves required to pay ultimate net losses (UNL) after netting out existing reserves on reported but unpaid claims (case reserves). This estimate includes an allowance for potential changes in such existing reserves for claims that have already occurred but yet to be reported.