The Trial Work Period (TWP) allows you to test your ability to work for at least nine months. During your TWP, you will receive full SSDI benefits regardless of how high your earnings might be as long as your work activity has been reported and you have a disabling impairment. Your TWP starts the first month you are entitled to SSDI benefits or the month in which you file for benefits, whichever is later. The TWP continues until you accumulate nine months (not necessarily consecutive) in which you perform what SSA calls "services" within a rolling 60-month period. SSA uses this "services" rule only to count TWP months. In 2018 SSA considers your work to be "services" if your gross earnings are more than $850 a month, or if you work more than 80 hours in self-employment in a month.