For many years the existence of CAS was debated and opinions differed about the nature and characteristics of the disorder. In 2007, ASHA released a technical report and position statement on CAS, recognizing the existence of the disorder and describing the characteristics. Since then researchers have continued to study CAS. Today, many experts agree that CAS results from a neurologically based difficulty with motor planning and programming for speech production with the following characteristics being more likely to discriminate CAS from other types of speech sound disorders:

What should be included in my assessment?
A motor speech examination is a critical component in an assessment for CAS because it allows the clinician to observe speech production and behaviors associated with CAS in utterances that vary in length and complexity. In a dynamic motor speech exam the clinician provides cues to facilitate performance which can be even more helpful because:
What tests are available to diagnose CAS?
There are several tests used to diagnose CAS, but not all have evidence of both validity and reliability which are important considerations for evidence-based practice. In a systematic review of tools used to assess CAS, Gubiana M.B., Paglianrin, K.C., et. al. (2015) reported on the validity and reliability of several CAS test. See a summary of the review here.
What if I am not sure?
Diagnosis of CAS can be challenging. Children with CAS often have concommitant language and phonologic disorders, and young children may have difficulty participating in evaluation procedures. All of these factors can make it difficult to confidently diagnose CAS. In such cases, clinicians may use a descriptive diagnostic statement that documents CAS cannot be confirmed or ruled out, followed by a list of characteristics observed in the assessment. Clinicians may also want to try a motor-based therapy approach and carefully monitor the child’s response to treatment. A robust response to a motor-based treatment approach suggests that motor planning may be an area of difficulty for the child.