Attention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental condition affecting millions worldwide. When it comes to diagnosis and medical billing, the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) is crucial. Within this system, code F90.9, titled “Attention-deficit hyperactivity disorder, unspecified type,” plays a significant role. This code is utilized when a patient meets the criteria for ADHD, but the specific presentation—whether predominantly inattentive, hyperactive-impulsive, or combined—is not clearly defined or documented.
F90.9 is a billable and specific code within the ICD-10-CM system, meaning it’s valid for reimbursement purposes and pinpoints a distinct diagnostic category. The code’s current iteration, effective as of October 1, 2024, is consistent with previous years, indicating its established and ongoing use in medical classifications. It’s important to note that while F90.9 is the American version, international versions of ICD-10 for ADHD may have slight variations.
The application of F90.9 encompasses cases previously referred to as “Attention-deficit hyperactivity disorder of childhood or adolescence NOS” and simply “Attention-deficit hyperactivity disorder NOS,” where NOS stands for “Not Otherwise Specified.” This highlights that F90.9 serves as a catch-all when ADHD is diagnosed, but further specification isn’t available.
Several terms are closely associated with F90.9, acting as approximate synonyms. These include “ADHD,” “Attention deficit hyperactivity disorder,” and historically relevant terms like “Hyperkinetic conduct disorder.” The inclusion of “Long term current use of medication for ADD and or ADHD” as a synonym emphasizes the code’s relevance in tracking medication usage related to ADHD.
Clinically, ADHD under F90.9 is characterized by developmentally inappropriate levels of inattention, impulsivity, and hyperactivity. Originating in childhood, these symptoms must be present to a degree that interferes with functioning in multiple settings, such as home and school. While symptoms often lessen as individuals reach late adolescence, some adults continue to experience the full spectrum of ADHD traits. Diagnostic criteria emphasize that some symptoms must be evident before the age of 7.
Common indicators of ADHD, which may lead to an F90.9 diagnosis when unspecified, include difficulty staying still, acting impulsively without thinking, and struggling to complete tasks. These behaviors, when persistent for more than six months and causing impairment across life domains, are key features of ADHD. While the exact cause of ADHD remains unclear, genetics and environmental factors are believed to play a role. A comprehensive evaluation by a qualified professional is essential for an accurate ADHD diagnosis and appropriate intervention strategies, which may involve medication, therapy, or a combination of both, alongside structured home and school environments.
For healthcare coding and billing, F90.9 falls under specific Diagnostic Related Groups (MS-DRG v42.0). The code itself has been stable since its introduction in 2016, with no changes through the 2025 edition, reflecting its consistent application in the ICD-10-CM system for classifying and diagnosing unspecified ADHD.
