Your regular monthly checks should start in one to two months (or so). However, it may take several additional months for all of your back benefits to be paid. This is because you will be first “overpaid” SSI. The reason for the SSI overpayment is that the Social Security Administration (SSA) usually calculates your SSI benefits without counting the amount of your social security disability benefits. The SSI “overpayment” then will be deducted from your past-due social security disability check. (Nevertheless, the total amount of benefits from both programs should be the same as if the offset were not involved.) Even if you are not overpaid SSI, the payment center will hold up payment of your past-due social security disability benefits to see if you will be overpaid SSI. All of these bureaucratic maneuvers take several months, possibly six months. It will be necessary for you to be patient.
If you will be getting more than a year’s worth of back SSI benefits, your benefits will be paid in two or three installments six months apart. The first two installments will each be equal to a year’s back benefits. The third installment will pay whatever is remaining. If you have outstanding debts or anticipated expenses for food, clothing, shelter or medical care or if you plan to buy a house, you may ask that more back benefits be paid with the first or second installment.