Objective: This research is designed to examine demographic differences between the ACTIVE sample and the larger, nationally representative Health and Retirement Study (HRS) sample. Method: After describing some relevant demographics (age, education, sex, and race/ethnicity), we use three statistical methods to determine sample differences—logistic regression modeling (LRM), decision tree analysis (DTA), and post-stratification and raking methods. When some differences are found, we create sample weights that other researchers can use to adjust these differences. Results: The ACTIVE sample is younger, more likely to be female, Black, and more highly educated than the HRS sample. Sample weights were created. Discussion: By using the resulting sample weights, all results of ACTIVE analyses can be said to be nationally representative based on HRS demographics.