<p>Researchers have long relied on United States Customs and Border Protection (CBP) apprehension data as a proxy for undocumented migration, yet the last time their validity was assessed was in 1995. Significant changes in the composition of migrants and border crossings since then raise questions about their continued validity. In this study, I provide an updated analysis using two independent data sources: the 2018 Guatemalan Census and annual estimates of undocumented Guatemalan arrivals to the United States from the Center for Migration Studies (CMS). Descriptive and regression analyses reveal a strong alignment between apprehensions, household migrations reported in the census, and estimated undocumented entries, suggesting that CBP apprehension data remained a reliable indicator of undocumented migration trends at both national and subnational levels during this period. These findings underscore the continued relevance of apprehensions and the need for regular empirical updates as migration dynamics evolve.</p>