July 24, 2017 18:45 Updated Follow To participate, you must be eligible to retire and immediately begin receiving unreduced retirement benefits on the date you enter the DROP. Related articles How do I begin participating in the DROP? What is the DROP? What new services from INPRS are available in 2018? When can I retire from PERF or TRF? Is there a limit on how much money I can make after retirement if I return to a PERF- or TRF-covered position?