The cutoff scores do differ between the 9 month and 10 month questionnaire intervals. The developers added the 9 month questionnaire with the third edition of ASQ in 2009, primarily to meet the needs of pediatricians following the American Academy of Pediatrics’ recommendations to screen at 9, 18, and 30 months. Research data was collected for the 9 month questionnaire, but there is a larger body of data for the 10 month questionnaire as it has been included on all previous editions of ASQ. If your program screens children along a continuum, as opposed to a one-time screening, the developers recommend using the 10 month questionnaire for children ages 9 months, 0 days through 9 months, 30 days (as well as children 10 months of age). However, many programs do use the 9 month questionnaire and its cutoffs. Another option is to initially use the 9 month questionnaire and then rescreen any child with scores in the monitoring or referral zone using the 10 month questionnaire and cutoffs prior to making referrals.