Oncology & Hematology Coding Alert

If you are confused about the Excludes notes in ICD-10-CM, you are not alone. Part of the problem lies in the fact that Excludes1 and Excludes2 sound like they are similar instructions, but they have completely different functions in diagnosis coding. Get those functions wrong, and you could be looking at denials, resulting in unnecessary — and expensive — claim delays and rework.

To help you avoid these problems, we’ve assembled a number of your frequently asked Excludes notes questions. Read on, and master this tricky ICD-10-CM guideline once and for all.

Question: If a Patient has 2 Conditions Linked by an Excludes1 Note, Which Code Do I Assign?

Answer: As you know, guideline A.12.a tells you an Excludes1 note is a “pure exclusion note,” and that you cannot code two linked conditions together because they cannot exist together. For example, as the guideline goes on to tell you, “an Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.”

In fact, this guideline is so emphatic that it uses capital letters and an exclamation point to inform you that the instruction means “NOT CODED HERE!”

But this guideline has been the cause of some confusion about exactly which code should be reported and which excluded. Fortunately, the American Hospital Association (AHA) ICD-10-CM Coding Clinic Volume 5, Number 4 (2018) explains that you should “assign only the code referenced in the Excludes1 note.”

For example, C20 (Malignant neoplasm of rectum) has an Excludes1 instruction telling you that it cannot be coded with C7A.026 (Malignant carcinoid tumor of the rectum). In the event you are coding a note in which the provider uses both terms to describe cancer of the rectum, you would assign C7A.026. However, in such cases, you should take the advice contained within guideline A.12.a, which tells you to query your provider, especially “if it is not clear whether the two conditions involving an Excludes1 are related or not.”

Question: What’s the Difference Between an Excludes1 and an Excludes2 Note?

Answer: 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.

For example, the C16.- (Malignant neoplasm of stomach) code group contains an Excludes2 note that allows you to code C7A.092 (Malignant carcinoid tumor of the stomach) along with a C16.- code when a provider documents both conditions in the note.

Coding tip: Always make sure you view the Excludes notes for the whole code category. In the above example, the Exclude2 instruction for the C16.- codes appears under the parent code, but it applies to all codes within the group. That means you should 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.

Question: Are Excludes Notes Reciprocal?

Answer: No. ICD-10-CM exclusions do not necessarily work both ways. An Excludes1 instruction under one code that tells you not to code a specified second code may not exist under that second code. So, to go back to our C20/C7A.026 Excludes1 example, you’ll find there is no corresponding Excludes1 note under C7A.026 or under parent code C7A.- (Malignant neuroendocrine tumors). That means, if your oncologist documents both a C7A.- code and C20, and the C7A.- code is the primary diagnosis, there is no instruction telling you that both conditions cannot be coded together when applicable.

Question: Can I Override an Excludes1 Note?

Answer: There are times when it is permissible to code two conditions together when an Excludes1 note does not allow it, though they are extremely rare.

Consider the following example, which appeared in the 2018 Q4 edition of AHA Coding Clinic. Here, the reader questions the coding of nutritional anemia along with unspecified anemia. In this example, D53.9 (Nutritional anemia, unspecified) has an Excludes1 note instructing the coder to report D64.9 (Anemia, unspecified) when the provider also documents “anemia NOS.”

In this example, the Coding Clinic advises it would be inappropriate to follow the Excludes1 guidelines and report only D64.9. That’s because “it would be contradictory to have a code for unspecified and another specified code for the same condition” as the Coding Clinic puts it. So, the Coding Clinic recommends assigning D53.9 only, especially as it has the specificity of nutritional anemia, reinforced by the inclusion term of simple chronic anemia.

This kind of example might be rare, but it’s important to keep your thinking cap on when addressing diagnosis codes that involve Excludes1 notes. The question offers a valuable lesson in following general coding principles over instructional notes, even Excludes1 notes. In this case, you would not code to the Excludes1 condition, even if ICD-10-CM instructs you to do so in the note.

Don’t forget: “Every year since the adoption of ICD-10-CM, there have been modifications to the Excludes1 and Excludes2 notes, as the folks in charge try to align their coding rules with coding realities,” says Sheri Poe Bernard, CPC, CRC, CDEO, CCS-P, author of the AMA book, Risk Adjustment Documentation and Coding. So, whether you still code manually, or use an electronic medical record (EMR), you will need to ensure your code choices incorporate the Excludes note revisions found in the ICD-10-CM updates when they take effect.