Sometimes a claim for Social Security disability benefits is denied after the date last insured (DLI) has passed. If that claimant files a subsequent claim for benefits, that subsequent claim may be denied based upon res judicata.
Res judicata, which is Latin for "the thing has been decided," is the legal principle that a final judgment is conclusive upon the parties in a subsequent litigation involving the same cause of action.
In the context of Social Security disability, the principle of res judicata keeps Social Security from having to decide the same claim over and over again. This makes sense, because a claimant's current medical condition is irrelevant to the determination of disability if the date last insured has gone by.
Nevertheless, res judicata has a limited application in Social Security disability claims. If there is new and material evidence, or a change in the listings, res judicata will not bar a subsequent claim. See HALLEX I-2-4-40.
New evidence can be current evidence. It just needs to relate back to the insured period. For example, a retrospective opinion from a treating doctor that the patient had serious functional limitations prior to the date last insured would constitute new and material evidence, and a new claim would not be barred by res judicata.
Also, remember to request reopening of the prior claim.