The Program for the International Assessment of Adult Competencies (PIAAC) is a multicycle international survey of adult skills and competencies sponsored by the Organization for Economic Cooperation and Development (OECD). The survey examines a range of basic skills in the information age and assesses these adult skills consistently across participating countries. The first cycle of PIAAC included three rounds: 24 countries participated in 2011-12 (round 1), 9 additional countries participated in 2014-15 (round 2), and 5 additional countries participated in 2017-18 (round 3). The United States participated in all three rounds of the first cycle of PIAAC. This is the second methodology report on the PIAAC Small Area Estimation (SAE). This report is a follow-up to the initial report and describes the methodology for creating model-based estimates for age and education groups. [For the first report, "Program for the International Assessment of Adult Competencies (PIAAC): State and County Estimation Methodology Report. NCES 2020-225," see ED622834.]