People with complex communication needs often require a comprehensive augmentative and alternative communication (AAC) assessment to maximize participation in daily interactions. Assessment of AAC is a complex process and limited practice guidelines exist. The purpose of this qualitative study was to explore how 25 speech-language pathologists with varying levels of experience approach the AAC assessment process. Participants were classified as either (a) General Practice Speech-Language Pathologists (GPSLPs), (b) AAC Clinical Specialists (AAC-CS), or (c) AAC Research/Policy Specialists (AAC-RS). In-depth, semi-structured interviews were conducted to explore the participants’ approach to AAC assessment. The results revealed that GPSLPs approach AAC assessment differently than the AAC-CS and AAC-RS; however, the Specialists reported a similar approach that may help guide the development of practice guidelines for AAC assessment.