Talked with him and he received a letter telling him to fill out a va form 21-4140 and he did. But it asked if he was working and he checked no. But the SSA reported taxable income "LTD" so they assumed he did not disclose it. I found under M21-1 part IV subpart ii 2.F5.a , automated monitoring for income sends a report to the VA of taxable income over the threshold. In return the VA sends the 21-4140 to explains the "working income". He was not working so he checked the no box for working. Since he was not working he has to now appeal and resubmit for his IU or not to stop his IU. Since he did not know what the 21-4140 was about he answered it correctly and checked no went to section 3 signed and sent it back not knowing they want to know about taxable income.