• An additional surplus is when there is more than one reinsurer sharing a line of insurance against a risk in excess of a specified deduction, each such reinsurer must contribute to cover any excess loss in proportion to its original exposure to such risk. Example: Withholding $100,000. Reinsurer A accepts a half share of $1 million over the stated $100,000. Reinsurer B accepts the remaining half of the $1 million premium.