The PROP account is an investment vehicle that was established on September 1, 2001 to allow members to elect to roll their lump sum DROP monies into it and earn a rate of return to be established by APRS annually. It is a notional account that does not actually contain cash, stocks, bonds or other securities like a 457-plan account. The PROP account is a bookkeeping account only and a member's PROP balance is invested right along with the other assets of APRS.
Under the rules adopted by the Board of Trustees, retiring and retired members may elect to defer receipt of all or a portion of their monthly annuity in order to defer the taxation of the deferred payments and to have the deferred benefits accumulate for later disbursement and later taxation in a PROP account.