The objective of this study is to examine the associations between the motivation to learn, basic skills (i.e., literacy and numeracy), and organized adult education and training (AET) participation among the middle-aged and older adults in the USA. Rapid technological advancement and globalization necessitate individuals to engage in lifelong learning to actively participate in society. However, little is known about the roles of motivation to learn and basic skills in the AET participation in the U.S. adult population. We obtained the data from the 2012/2014 Program for International Assessment of Adult Competencies restricted-use file and adults aged 50 years and older (n = 2,580) are included. Structural equation models are used to examine (1) any AET, (2) formal AET and (3) non-formal AET participation as a function of the motivation to learn latent construct, literacy, numeracy, and other covariates. Results showed that the motivation to learn, literacy and numeracy are all positive predictors of non-formal AET participation. Only motivation to learn is associated with formal AET participation. Findings from this study may inform future interventions as well as policy changes to promote specific types of organized AET programs among older adult population in the USA. [This paper will be published in the "International Journal of Lifelong Education."]