Little is known about how special education services received by students with Autism Spectrum Disorders (ASDs) differ by age, disability severity, and demographic characteristics. Using three national datasets, the Pre-Elementary Education Longitudinal Study (PEELS), the Special Education Elementary Longitudinal Study (SEELS), and the National Longitudinal Transition Study-2 (NLTS2), this study examined the age trends in special education services received by students with ASDs from preschool through high school. Elementary-school students with ASDs had higher odds of receiving adaptive physical education, specialized computer software or hardware, and special transportation, but lower odds of receiving learning strategies/study skills support than their preschool peers. Secondary-school students had lower odds of receiving speech/language or occupational therapy and of having a behavior management program, but higher odds of receiving mental health or social work services than their elementary-school peers. Both disability severity and demographic characteristics were associated with differences in special education service receipt rates. [This paper was published in "Journal of Special Education" v48 n3 p167-179 Nov 2014 (EJ1042096).]