Parents may be well placed to deliver therapeutic support to their own autistic preschool children. Parent-implemented Early Start Denver Model (P-ESDM) is one well-researched program for coaching parents to use strategies in daily routines to support child development. This qualitative study examined the perceptions of parents of autistic preschool children who participated in a two-tiered 20-week P-ESDM program. This program was novel in that it involved group delivery of P-ESDM as well as a two-tiered approach to support provision. Semi-structured interviews were conducted with the nine parents of seven autistic preschool boys who participated in the program. Data were analyzed using reflexive thematic analysis. Four key themes and 13 subthemes were developed. The themes centered on (a) program accessibility and participation, (b) experience of the two-tiered coaching process, (c) commitment and perseverance, and (d) outcomes. Parents perceived the program to be feasible, acceptable, and effective and gave recommendations for improving future tiered P-ESDM supports. The mixed perceptions from parents suggest the need for flexible, individualized support. Understanding the reported strengths and barriers of this program could allow future programs to better meet the needs of diverse families.