Oncology & Hematology Coding Alert

Do you know the difference between Excludes notes?

The release of the 2021 ICD-10-CM code revisions provides a timely opportunity to revisit your knowledge of diagnosis coding guidelines, especially the often misunderstood Excludes instructions.

Excludes1 Is a Pure Exclusion Note

ICD-10-CM guideline A.12.a. for Excludes1 uses capital letters and an exclamation point to inform you that an Excludes1 note is a “pure exclusion note” that means “NOT CODED HERE!” The note means you cannot code two specified conditions together because they cannot exist together.

But this guideline has been the cause of some confusion about exactly which code should be documented and which excluded. Fortunately, the AHA ICD-10-CM Coding Clinic explains that you should “Assign only the code referenced in the Excludes1 note” (Source: Coding Clinic 2018 Vol. 5, No. 4).

2022 ICD-10-CM Tabular Addenda Example: The instruction under new parent code L24.Ax- (Irritant contact dermatitis due to friction or contact with body fluids) lists codes from new parent group L24.B- (Irritant contact dermatitis related to stoma or fistula) as Excludes1 codes. If a provider documents diagnoses from both groups, the Excludes1 instruction tells you that you should only use a code from L24.B-.

But Sometimes You Can Report Both Dx

The Excludes notes guidelines continue with an important exception to the Excludes1 “not coded here” rule. This allows you to report excluded codes “when the two conditions are unrelated to each other,” which should be clearly supported by documentation.

Expert coding tip: ICD-10-CM guidelines encourage you to query your provider “if it is not clear whether the two conditions involving an Excludes1 are related or not.”

Excludes2 Means “Not Included Here”

A condition identified by an Excludes2 note is medically related to the main condition but can occur independently of that condition. It is separately reportable under a different ICD-10-CM code and not included in the ICD-10-CM code or group under which the Excludes2 note appears.

2022 ICD-10-CM Tabular Addenda Example: ICD-10-CM has changed the Excludes1 instruction under D64.81 (Anemia due to antineoplastic chemotherapy) to an Exludes2 code for 2022. This means if your provider documents D64.81 and D61.1 (Drug-induced aplastic anemia) together, you can now use both codes.

How to Avoid Excludes Note Problems

• Be aware of mistakes. The change to the D64.81 Excludes note shows you that “many codes were assigned Excludes1 notes in the initial publication of ICD-10-CM when they should have been assigned Excludes2 notes,” warns Sheri Poe Bernard, CPC, CRC, CDEO, CCS-P, author of the AMA book, Risk Adjustment Documentation and Coding.
• Don’t assume that Excludes notes are reciprocal. ICD-10-CM exclusions do not necessarily work both ways. An Excludes1 instruction under one code that tells you not to code a second code may not exist under the second code.
• Make sure you view the Excludes notes for the whole code category. Be sure to look to the instructions under each level in a code group as well as the ones that may accompany a specific code. Excludes notes at the three-character level apply to all codes in that family, including any five-character codes in the family that have additional Excludes notes under them.
• Make sure your manuals and EMRs are up to date. “Every year since the adoption of ICD-10-CM, the folks in charge have been modified the Excludes notes to align coding rules with coding realities,” says Bernard. So, whether you still code manually, or use an electronic medical record (EMR), you will need to ensure your code choices incorporate the revisions found in the yearly ICD-10-CM addenda when they take effect every October 1.
• Make sure everyone concerned is aware of the changes. All coding staff, billers, and providers in your practice should be aware of any ICD-10-CM changes when they are implemented.

Bottom line: Take heart. Confusion over the mistakes in, and constant revisions to, the Excludes instructions is widespread. So, remember: “If you are confused about the Excludes notes in ICD-10-CM, you are not alone. The folks in the government who created these notes years ago apparently were confused, too,” Barnard jokes.