This Corrective Action Decision Document identifies and rationalizes the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office's selection of recommended corrective action alternatives (CAAs) to facilitate the closure of Corrective Action Unit (CAU)168: Areas 25 and 26 Contaminated Materials and Waste Dumps, Nevada Test Site (NTS), Nevada, under the Federal Facility Agreement and Consent Order. Located in Areas 25 and 26 at the NTS in Nevada, CAU 168 is comprised of twelve Corrective Action Sites (CASs). Review of data collected during the corrective action investigation, as well as consideration of current and future operations in Areas 25 and 26 of the NTS, led the way to the development of three CAAs for consideration: Alternative 1 - No Further Action; Alternative 2 - Clean Closure; and Alternative 3 - Close in Place with Administrative Controls. As a result of this evaluation, a combination of all three CAAs is recommended for this CAU. Alternative 1 was the preferred CAA for three CASs, Alternative 2 was the preferred CAA for six CASs (and nearly all of one other CAS), and Alternative 3 was the preferred CAA for two CASs (and a portion of one other CAS) to complete the closure at the CAU 168 sites. These alternatives were judged to meet all requirements for the technical components evaluated as well as all applicable state and federal regulations for closure of the sites and elimination of potential future exposure pathways to the contaminated soils at CAU 168.