First, it's a royal pain in the ass.
Secondly, expect that the SSI workers will **** up things.
Thirdly, make sure you allocate plenty of time whenever you have to deal with SSI, either in person or over the phone. Expect to wait multiple hours of sitting in the waiting room, or an hour of being on hold, only to talk to the person for two minutes and then mysteriously get hung up upon, only to call them back and wait on hold for another hour.
Fourthly, while there's so many requirements, read up on the eligibility requirements, and the appeals processes, and know them to the letter, because you don't want to get into a situation where they claim they overpaid you, even though you were following their instructions.
Fifthly, if you have to mail anything, make copies beforehand, and mail it out certified return receipt requested, because they will inevitably claim that they never received your paperwork.
Sixthly, make sure you have all your paperwork in order, which makes things go smoother for the worker and less stressful for yourself.
Seventhly, keep track of the assets and resources. I think for an individual now, you can have up to $2,000 in the bank, plus a house and a car. At $2,001, they consider you overpaid. If the person is on SSI, and they think they overpaid you, they'll reduce the monthly check down. If the person isn't on SSI, they'll demand you pay out of your pocket.
Eightly, look up in your state for Medicaid waiver services. This isn't like regular Medicaid for the poor, which are based on income and assets. This is for those who have specific disabilities, regardless of income and assets. It depends on the state, though. Not to get political, but a blue state is more generous with waiver services than a red state, so it may either be easy to get into, or near-impossible, or may take years.
The waiver services helps with paying medical bills (think of it like supplemental insurance with paying for deductibles and co-pays your regular insurance doesn't pay), as well as provides other services to help the individual live a better life.
Ninthly, keep track of all contacts you make with SSI, including the name of the person, the date, and the conversation. This helps when they claim you never contacted them.
Tenthly, make sure you inform them of any changes, which includes change of phone number or address, or job situation, or income.
And one to grow on: Just remember throughout the process that this is your taxpayer dollars at work. Then take your blood-pressure meds.