Many people are denied Social Security Disability Insurance Benefits and Supplemental Security Income because Social Security does not believe the person will be disabled for one year.
To be disabled, a person must show an "inability to engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment which can be expected to result in death or which has lasted or can be expected to last for a continuous period of not less than 12 months." 42 U.S.C.§ 423(d)(1)(a).
I usually see "durational denials" when the person is alleging disability due to a traumatic accident or a diagnosis of breast cancer. Social Security's rationale is that although the person is disabled when they filed the application, the person will be able to return to some type of work activity with one year of the disabling event.
These types of cases require close attention to the medical evidence. Do the medical records show that the condition has improved or that it is improving? An opinion from the claimant's treating physician as the functional limitations and if said limitations will last over a year is also helpful.
You should consider speaking to an experienced disability attorney if your application for Disability Insurance Benefits or Supplemental Security Income is denied because Social Security states your disability will not last for a year.