I have another co-sponsor but he only get pension as an income. He gets pension more than poverty line.
My question:
1. What document he should send and USCIS will accept it to prove that he get pension as long as it is tax free?
2. Would being diagnosed as having PTSD be a disqualifier as a co-sponsor?

Thanks &

1. Nothing about income I-864 gets sent to USCIS, it gets brought to the interview or sent to National Visa Center per the requirements of the particular consulate you are dealing with.

2. Medical conditions are not considered, just financial information for affidavit of support.

The pensioned person has a document awarding them the pension. Send a copy of that along with a note indication which part of the IRS code, if any, exepts the person from filing a tax return.