Universal developmental screening during pediatric well child care detects early delays in development and is a critical gateway to early intervention for young children at risk for Autism Spectrum Disorders (ASD). Developmental screening practices are highly variable, and few studies have examined screening utilization for children at risk for ASD. Currently, a two to four year gap exists between first recognition of concern and referral for diagnostic evaluation of ASD. The purpose of the current study was to examine the influence of developmental screening practices on timing of ASD diagnoses in the state of New Hampshire through health care administrative claims data from the New Hampshire Comprehensive Health Care Information System. The study examined differences in mean age of ASD diagnosis for a sample of 144 children who were born between January 2007 and December 2010 who received or did not receive universal screening during well child care, as well as those who received screening at multiple time points and those who received screening at one time point. Further, the study examined the association between gender, geographic region and provider type on age at diagnosis of ASD. The data suggested no significant differences in mean age of ASD diagnosis for children who received a standardized developmental screening during well-child care and those who did not. Statistically significant differences in mean age of diagnosis were found between children who were screened at one time point and children who were screened at more than one time point. Children screened at more than one time point were diagnosed later than those screened at one time point. Geographic region was a significant predictor on age of ASD diagnosis accounting for approximately 31% of the variance. Continued efforts to measure screening practices through use of administrative claims data may increase utilization and improve access to intervention for young children at risk for ASD. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]