As with other forms of LEED documentation, the HPD must be valid at the time the product was purchased and used, even if it is expired by the time the LEED submission is completed.

The key text from the LEED Reference Guide says, "Qualifying HPDs developed under the Open Standard version 1.0, 2.0, 2.1 or subsequent versions of the standard are eligible for documenting credit achievement if the HPD is still valid at the time that the product is purchased and used on a project."

The HPD must otherwise be LEED compliant. See HPDC's guidance on LEED v4 compliance here.