Primary Care Coding Alert

Question: A payer denied a claim for an adult patient with attention deficit hyperactivity disorder (ADHD) when I used the code that the ICD-10-CM index directed me to when I searched for the condition. I read the ADHD article published in Primary Care Coding Alert Volume 25, Number 5, but that code isn’t mentioned. Why can’t I use that code?

Nevada Subscriber

Answer: As you’ve discovered, when you look up attention deficit disorder (ADD) in the ICD-10-CM index, it directs you to F98.8 (Other specified behavioral and emotional disorders with onset usually occurring in childhood and adolescence). This code is commonly denied, especially when it’s describing a diagnosis of adult ADHD. This is because it’s not the most specific code available.

ADD/ADHD is a behavioral and emotional disorder that typically begins in childhood, which is why the index directs you to F98.8. However, when you look up F98.8 in the tabular list, you see four synonyms listed:

• Excessive masturbation
• Nail biting
• Nose-picking

This information tells you that those conditions warrant the use of F98.8. ADHD is not included in this list, but in all fairness, it’s also not excluded. If you look in the index starting with “Attention (to),” you will see underneath it says, “deficit disorder or syndrome,” which indeed points to F98.8. However, indented under that entry in the index is “with hyperactivity,” which says to see “Disorder, attention-deficit hyperactivity.” When you go to “Disorder” in the index and look at “attention-deficit hyperactivity” underneath it, the index points you to F90.9 as a starting place.

When you follow that through to the tabular list, you end up with the Chapter 5 ADHD-specific codes. ADHD and ADD are often used interchangeably, so even if an adult presents with ADHD without hyperactivity as a symptom, coding to F90.0 (Attention-deficit hyperactivity disorder, predominantly inattentive type) is the best-fitting, most specific code compared to F98.8.

Take-home message: The index never gives a complete picture, so it’s best to instead use the index as just a starting place to determine the most accurate code(s) to report the diagnosis of a specified disorder.