Extended Period of Eligibility
If your earnings are "substantial" (see Substantial Gainful Activity), then after you have gone through the nine month Trial Work Period and the three month extended benefitsperiod, you willbe placed in the category: "Extended Period of Eligibility." During this time you no longer receive monthly benefits but your Social Security file remains open, and you are entitled to receive your SSDI benefit in any month that your earnings drop below the "substantial" amount.
If Your Earnings Fall Below the Substantial Threshold: All you have to do to claim the benefit for any month in which your countable earnings are below the "substantial" amount is take proof of income to your local Social Security office. They will order a check cut for that month.
Duration: The Extended Period of Eligibility will continue for thirty-six months after the nine months of the Trial Work Period and the additional three months of benefits that follow it. In other words it continues for another three years after the initial trial year.
Resumption of Benefits: If, during the Extended Period of Eligibility, you are unable to continue working because of your medical condition, your benefits will resume immediately. Also, during that time, in any month or months that your income falls below the "substantial" level (in 2014, $1,070 per month; $1,740 for blind claimants), you are entitled to receive your regular SSDI benefit for that month.
Medicare: Your Medicare benefits will continue. There is no cost for Part A coverage. You will have to pay the Part B and D premiums directly since you will be receiving no SSDI payments from which they may be withheld. There may be a program to assist you with the payment of Part B premiums. See Medicare -- Financial Assistance.
Under a federal law called Ticket to Work (See SSA - Ticket To Work), your right to have Medicare is extended another 4 years beyond the 9 month Trial Work Period, the additional 3 months and the 36 months of the Extended Period of Eligibility. That's 8 years of continued Medicare after the Trial Work Period expires. During this period, if you were eligible for free Part A coverage before, you will continue to receive Part A coverage free for the entire period.
At the end of that time, you may continue your Medicare but you will have to pay premiums for Part A as well as Part B and Part D.
If You Become Disabled Again During the Extended Period of Eligibility, you may resume your benefits. Depending on when your file was last reviewed, SSDI may request a new application, but you will not be subjected to the five month waiting period. Your benefits will start accruing immediately even if processing delays the actual payments for a month or two.