Where do I find experts in SSI?

Ignore your brother. Ask the lawyer your questions.

HOW DOES MONEY FROM A TRUST THAT IS NOT MY RESOURCE AFFECT MY SSI BENEFITS? Money paid directly to you from the trust reduces your SSI benefit.
Money paid directly to someone to provide you with food or shelter reduces your SSI benefit but only up to a certain limit. No matter how much money is paid for these items, we subtract no more than $265.00 (in 2017) from your SSI check for the month you receive the items.
Money paid directly to someone to provide you with items other than food and shelter does not reduce your SSI benefits. (Items that are not "food or shelter" include medical care, telephone bills, education, entertainment, etc.)

SSA website

The problem: Brother was sent two checks from property tax rebate office. Tried to cancel the rebate as I played property tax from mom estate. The lady said brothers expenses should have been around $860. The check are the amount to cover his expenses. Made no sense to me. Called lawyer. She said brother can cash checks but can only use the money for things that the trust would be allowed to pay for. Brother called SS office. Told he had to cash checks and his SS I was being reduced or stopped until he pays the money back. So lawyer had different answer than SS. That's were I need expert. Not on normal rules. But when weird things come up.

Forgot, a judge determines if a Special needs trust is given. Once it is enforced it cannot be broken. Its lifelong. Any monies left go to the beneficary. Cannot be calculated by Social Security or SSI as income but they do need to be aware there is one.

Barbara, if I recall correctly, your brother wants control of "his" money and wants to have control over investing it.

You cannot give him money. It will disqualify him from SSI. Someone (the trustee) needs to pay for items other than food and shelter. (At least that's what I'm getting from reading on the SSA website.) SSI is intended to be there to pay for food and shelter. You don't want him to lose SIS because then he would lose Medicaid, yes?

Is that what the lawyer has told you? Let me guess...your brother doesn't like the answer.

Barbara, I suspect the difference in the answers had to do with the difference in the way the question was asked.

Have the lawyer reach out to SSI.

Alert: The brother should stop calling Soc. Sec. and let the rep. payee and trustee handle it. He should not have access to be able to cash checks, there are rules to follow, and he can really mess this up. He needs to cooperate, is probably upset because a special needs trust prevents him from access to his money. If he is so smart, sit down with him and have him read the trust and SSI rules/guidelines.

Hadnuff,
The weird thing is that brother had access to cash the checks, when the money should have gone into the trust account.

Send, my grandmother received some property tax rebate checks in the first year I was here. I had learned she qualified for a considerable discount on her property taxes due to program in Illinois called "Senior Freeze," but the trust wasn't filing her paperwork each year to get the reduction. The tax assessors office sent rebate checks directly to her, not to the trust. I could've turned them over to the trust, but... I ended up using the money for her needs instead. The trust was the one responsible for overpaying for a decade. They wasted over $10k overpaying her property taxes just because they wouldn't file the basic paperwork.

Regardless, the refund will go to the person in whose name the taxes are paid. It doesn't matter that trust paid/overpaid the tax. That's my experience.

I don't know if my input will help...

I just recently took my 78 yo father to apply for SSI. He does qualify, as being (1) elderly, and (2) low income, which gives the 2 qualifications for SSI benefits. SSA will only give up to $500 without the beneficiary showing they have bills/expenditures to pay. If someone is being cared for by others, they won't qualify for their max amount of SSI they will otherwise receive.  

E.g., in my dad's case, he lives at my brother's house and pays no part of bills, rent, food.  He can only qualify to receive up to $500 total without having verified expenses.  

If there are bills, rent, medical expenses that can be documented for SSA, they will provide $700 total (SS + SSI) for any indigent, elderly person.

I'm not sure what the issue is, exactly, in your case, but I hope this is helpful info of what SSI will provide, and under what circumstances.