Primary Care Coding Alert

Know when, when not, to “code here.”

“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,” says Sheri Poe Bernard, CPC, CRC, CDEO, CCS-P, author of the AMA book, Risk Adjustment Documentation and Coding.

Part of the problem lies in the fact that Excludes1 and Excludes2 sound like they are similar notes, 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 avoid these problems, take a look at the following guide. And make sure you read to the end, where we’ve included some great tips for avoiding coding problems involving Excludes instructions.

Don’t Code These Codes Here …

The ICD-10 guidelines for Excludes1 notes could not be more emphatic. To make sure you don’t misunderstand the instruction, Guideline A.12.a. even uses capital letters and an exclamation point to inform you that an Excludes1 note is a “pure exclusion note” that means “NOT CODED HERE!”

Essentially, an Excludes1 note means you cannot code two conditions together because, medically, they cannot exist together. They are generally mutually exclusive. For example, the Excludes1 note under I12.- (Hypertensive chronic kidney disease) lists several codes in the I15.- (Secondary hypertension) group that you cannot code together.

Why? “There is an assumption in coding that almost all hypertension is renal in origin,” says Marcella Bucknam, CPC, CCS-P, COC, CCS, CPC-P, CPC-I, CCC, COBGC, revenue cycle analyst with Klickitat Valley Health in Goldendale, Washington. So, any diagnosis in the I12.- group makes any of the secondary hypertension diagnoses redundant. Or, to put it another way, “you should never see I15 and another hypertension code on the same claim,” according to Bucknam.

… but Note This Important Exception

The Excludes notes guidelines continue with an important exception to the Excludes1 “not coded here” rule. This allows you to code excluded codes “when the two conditions are unrelated to each other.”

You’ll find plenty of exceptions whenever you dip into the R00-R99 signs and symptoms codes found in Chapter 18. Look up R52 (Pain, unspecified), for example, and you’ll find a long list of Excludes1 codes. Obviously, if your provider chooses one specific pain diagnosis, such as M54.9 (Dorsalgia, unspecified) (i.e. back pain), you would report only that without the less-specific R52. But if your provider notes that the patient reports back pain in addition to generalized pain, then it would be possible to code both M54.9 and R52 together.

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

Know the Difference Between Excludes Notes …

As ICD-10 guidelines put it, an Excludes2 note means a specific condition is “not included here.” In other words, 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 under the ICD-10-CM code under which the Excludes2 note appears.

Under I21.- (Acute myocardial infarction), for example, you’ll find three Excludes2 codes, including I25.2 (Old myocardial infarction). This means that a previous myocardial infarction (MI) is not included in the code choice for a new MI. So, if a patient has experienced both a new and an old MI, you should not assume that coding for the new MI with I21.- automatically includes the information that the patient has had an old MI. Under these circumstances, you will need to code both I21.- and I25.2.

… and Be Aware of Mistakes

“A problem that arises is that many codes were assigned Excludes1 notes in the initial publication of ICD-10-CM when they should have been assigned Excludes2 notes,” Barnard warns. “For 2020, these errors continue to be corrected. For example, subcategory D04.0 [Carcinoma in situ of skin of lip] had an Excludes1 note in 2019 for D00.01 [Carcinoma in situ of labial mucosa and vermilion border]. For 2020, this note has been changed to Excludes2, meaning if both conditions are documented, both should be coded,” Barnard adds.

How to Avoid Excludes Note Problems

• Don’t assume that Excludes notes are reciprocal. ICD-10 exclusions do not necessarily work both ways. The I12 Excludes1 note for I15, for example, does not have a corresponding Excludes1 note for I12 under I15.
• 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 the specific code itself to find all the Excludes notes that apply to a specific code. For instance, 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, 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 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 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 changes when they are implemented.