A computer-based apparatus for representing and acting on an indexed reversionary annuity, including a memory unit for at least one specially programmed computer configured to store computer readable instructions and an initial income amount, and a processor for the at least one specially programmed computer configured to execute the computer readable instructions to determine a set of indexing parameters P and generate an updated income amount at an end of a specified indexing term T based in part on performance of at least one index and the set of indexing parameters P.