Can you collect SSI while in jail?

No. You need to be available and looking for work. In California, the unemployment form has a specific question that says is there any other reason besides illness that you cannot accept full time work. If you are incarcerated obviously that is a reason why you cannot accept employment. Answering yes to that question will automatically stop your unemployment check from being sent out pending a followup by someone in the Employment Development Department's Unemployment Office. This followup will usually be via a telephone interview which you will not be able to partake in due to you not being at home to get that call. Long story short, being truthful will get your benefits stopped. Being dishonest (or rather having someone on the outside being dishonest by filling out your unemployment form every two weeks for you) is fraud. Both you and the person who is your accomplice in this deceitful undertaking face long prison terms if the conspiracy is uncovered.