Radiology Coding Alert

Answer: While Excludes1 and Excludes2 instructions sound like they are similar notes, the two have completely different functions in diagnosis coding.

According to ICD-10-CM Official Guidelines, Section I.A.12.a, an Excludes1 note is a “pure excludes note.” This means you cannot code two conditions together because they don’t occur together and are generally mutually exclusive. For added emphasis, the guideline adds the words “NOT CODED HERE!” in capital letters and with an exclamation point.

If you receive documentation listing two diagnoses that are subject to an Excludes1 instruction, you’ll exclusively report the code reported in the Excludes1 note, according to the American Hospital Association (AHA) Coding Clinic^® for ICD-10-CM and ICD-10-PCS (Q4, 2018).

Exception to the rule: You can code Excludes1 codes together when “the two conditions are unrelated to each other,” the ICD-10-CM Official Guidelines state. For example, your provider documents the patient is experiencing generalized pain in addition to back pain. If the documentation indicates the generalized pain is not caused by the back pain, then you can override the Excludes1 note and assign R52 (Pain, unspecified) along with M54.9 (Dorsalgia, unspecified).

On the other hand, an Excludes2 note indicates a certain condition is “not included here.” What this means is that one condition may not be part of the main condition, but the patient may experience both conditions at once. For example, a patient could present to your facility with cluster headaches, coded to G44.009 (Cluster headache syndrome, unspecified, not intractable), as well as migraines with aura, coded to G43.109 (Migraine with aura, not intractable, without status migrainosus).

Parent code G44.- (Other headache symptoms) carries an Excludes2 note that lets you assign codes from the G43.- (Migraine) code family.

Remember: Review the instructions under each level in a code group, in addition to the ones that may accompany specific codes, to find any Excludes notes that apply to the code(s) you’re assigning. Excludes notes at higher levels (such as the three-character level) apply to codes in lower levels (such as five-character levels), even if the codes further down in the family have additional Excludes notes under them.