Which entity establishes the official ICD-10-CM and ICD-10-PCS coding guidelines that inpatient coders must follow?

The correct answer is the entity that establishes the official ICD-10-CM and ICD-10-PCS coding guidelines, known as the Cooperating Parties. This group is responsible for creating and maintaining the coding guidelines that all coders must adhere to when assigning diagnoses and procedure codes. The Cooperating Parties include the American Hospital Association (AHA), the American Health Information Management Association (AHIMA), the Centers for Medicare & Medicaid Services (CMS), and the National Center for Health Statistics (NCHS).

These guidelines are essential for ensuring consistency, accuracy, and compliance within the healthcare system, as they provide detailed instructions on how to apply the coding systems effectively. They also play a critical role in ensuring that coders interpret the codes in a standardized way, which is vital for proper billing, reimbursement, and health data reporting.

While other entities such as the state health department and the American Health Information Management Association contribute to healthcare and coding practices, they do not have the authority to set official coding guidelines like the Cooperating Parties do. Similarly, a national coding board is not recognized as the official authority for these guidelines. Thus, the Cooperating Parties are the key organization that outpatient and inpatient coders must follow.