With the advent of the 4th industrial revolution, having key competencies and skills is essential to maintain a job, and lifelong learning should be secured. This study was to identify the status of Koreans’ basic competencies and technology use and examine the effects of these variables on the NEET trend and income of Koreans. Data were from the International Assessment of Adult Competencies (PIAAC) 2018 Koreans aged from 16 to 65 years old. A series of regression analyses were employed to analyze data. The findings revealed that for literacy, the mean difference for education levels was higher than that for the age group. For numeracy, the mean difference for the age group was higher than that for education levels. As Koreans age, their competencies of numeracy also decrease. The result showed that the higher the numeracy score was, the lower the NEET tendency was. However, numeracy did not show a significant effect on income. Skills such as writing reports and using statistics outside of work are infrequent, but those skills help reduce the possibility of falling into NEET. The result suggested that it is necessary to enhance the lifelong learning so that adults can maintain literacy, numeracy and problem solving skills in technology-rich society and work.