Radiology Coding Alert

Question: I’m new to medical coding, and the ICD-10-CM Official Guidelines regarding Excludes1 and Excludes2 notes still confuse me.

Could you please clarify the difference between the two notes?

Florida Subscriber

Answer: While they sound similar, Excludes1 and Excludes2 instructions are very different in practice for diagnosis coding.

According to the ICD-10-CM Official Guidelines, section I.A.12.a, Excludes1 is a “pure excludes note,” which means the listed code should never be used at the same time as the code listed above the Excludes1 instruction. Another way of interpreting the rule is that the two conditions cannot occur together.

Example: You’d report S52.001A (Unspecified fracture of upper end of right ulna, initial encounter for closed fracture) if the provider diagnoses the patient with an unspecified closed fracture of the upper end of the right ulna. Parent code S52.- (Fracture of forearm) features an Excludes1 note that lists S58.- (Traumatic amputation of elbow and forearm). In this case, a forearm fracture (S52.-) cannot exist at the same time as an amputated forearm (S58.-).

On the other hand, according to the ICD-10-CM Official Guidelines, section I.A.12.b, an Excludes2 note represents “not included here.” This means that the condition is not a part of the condition represented by the initial diagnosis code, “but a patient may have both conditions at the same time.”

Example: Parent code S52.- also features an Excludes2 note that includes S62.- (Fracture at wrist and hand level). You could come across a report where the provider diagnoses the patient with a closed fracture of the upper end of the right ulna and a closed fracture of the first right metacarpal bone. In that case you’d report S52.001A and S62.201A (Unspecified fracture of first metacarpal bone, right hand, initial encounter for closed fracture) together.

In short, Excludes1 means the two codes may never be used together, while Excludes2 allows two or more codes to be used together, when appropriate.