A computer assisted coding system (CACS) is a computer software application that analyzes health care documents and produces appropriate medical codes for specific phrases and terms within the document.
Similar conceptually to "spell check," the software uses natural language processing (NLP) in order to highlight key terms and phrases for ICD-9 CM, ICD-10 CM and CPT coding. In addition, CACSs analyze the context to determine whether or not a particular instance requires coding. For example, the software can determine that the term "cancer" requires coding when it's a diagnosis, but not when it is referring to a "family history of cancer."
Traditionally such coding is performed by people called coders, but the shift to a technology driven health care system has increased the necessity and demand for coding -- especially with the growth in electronic health record (EHR) implementation and the transition to ICD-10-CM. This has led to a hybrid system, in which CACS perform a majority of the coding, especially on routine procedures, and coders address more complex scenarios while auditing the CACS output.
According to the American Health Information Management Association (AHIMA), CACS offer several advantages over manual coding, including increased productivity and efficiency in coding and the consistent application of coding rules. However, the cost of the software and the increased potential for errors are potentially detrimental.