Once you have qualified for SSDI, you have nine months as a test period to work. This is called a trial work period. The months do not have to be consecutive, but the trial period ends in 60 months regardless of whether or not you used the entire nine-month period.
Any month in which you earn more than $940 is counted as one of the nine months. Whatever you earn during a trial month does not affect your SSDI benefits. In other words, the substantial gainful activity threshold of $1,310 a month if you are disabled or $2,190 if you are blind would not apply.
If you reach the end of the nine-month trial work period, you can continue to work under an extended period of eligibility of up to 36 months additional months. Your SSDI benefits will continue to be paid for any month that you do not exceed the substantial gainful activity earnings limits. You will not receive SSDI for any month during the extended period that you exceed the earnings limits.
You need not be concerned about having to reapply for SSDI and go through the entire evaluation process all over again should you discover that your medical condition does enable you to continue working. You have up to five years to ask Social Security to restart your SSDI payments without needing to file a new application or be subjected to delays as your medical condition is reviewed. Expedited reinstatement avoids delays in restoring benefits.