A technical denial is a denial for non-medical reasons. In other words, the denial has nothing to do with whether your medical impairment fits the criteria for a disability.
While many applicants are denied disability benefits for medical reasons, about half of applicants who are seeking Social Security Disability Insurance (SSDI) receive technical denials, according to the Social Security Administration. Technical denials are issued to about a quarter of Supplemental Security Income (SSI) applicants.