Do skills protect against exclusion in adult ages, and how important are the skills acquired before the age of 16 years versus those acquired later on? We match the scores on numeracy and literacy skills from the 2011 PIAAC for young adults backwards to grade point average (GPA) data from compulsory school education, measured at the age of 16 years (GPA16), and forwards to employment and education register data 2 years after the PIAAC test. There is a high correlation between GPA16 and PIAAC scores even when controlling for parental background, health status, and completion of post-compulsory school education. Including both GPA16 and PIAAC scores in a model of the probability of NEET status 2 years after the PIAAC test shows three times as large differences associated with GPA16 scores than with PIAAC scores, even though the PIAAC test is taken closer in time than the GPA16 results.