Most clients prefer … and most lawyers offer … a “contingent fee,” a fee paid only if they win. The usual fee is 25% (one-quarter) of back benefits up to a maximum amount set by SSA, which is currently $6,000. The fee comes from those benefits that build up by the time you are found disabled and benefits are paid. No fee comes out of current monthly benefits.
Although the usual fee will not normally exceed the maximum fee of $6,000, if your lawyer has to appeal after the first administrative law judge hearing, your contract might allow for a fee greater than $6,000. Even in this circumstance, though, your fee is likely to not be greater than 25% of back benefits.
In addition to the fee, many attorneys expect you to pay the expense of gathering medical records, obtaining medical opinion letters, etc.