As nouns the difference between deductible and proration
is that
deductible is (us|insurance) amount of expenses that must be paid out of pocket before an insurer will pay any expenses while
proration is (telecommunication) budgeting the proportional distribution or allocation of parameters, such as noise power and transmission losses, among a number of tandem-connected items, such as equipment, cables, links, or trunks, in order to balance the performance of communications circuits.
As an adjective deductible
is that can be deducted.