See: Basis of Attachment.
***
Simplistically, the segregation of all premiums and losses attributable to policies having an inception or renewal date within a given 12 month period.
***
Underwriting result based on written premiums and ultimate losses from loss events falling within the same accounting period, where the accounting period is the period covered by the insurance policy or reinsurance agreement, regardless of when the premiums and losses are actually reported, booked, or paid. See Accident year experience and Calendar year experience. Underwriting losses are typically offset by investment income.
Insurance Encyclopedia
Underwriting year system
Method in proportional treaty reinsurance whereby all premiums and losses relating to an underwriting year are accounted to that year regardless of when such losses arise or when such premiums and losses are paid.
Undiscovered loss clause
Cargo clause providing cover for losses that are not discovered until the boxes are opened after the termination of the risk. Externally the box or package appears in good condition, but contains concealed damage.
Undocumented service
A service that has been billed on an insurance claim for which there is either insufficient or no supporting documentation to validate the service or procedure in the patient’s medical record.