Coding Corner: Excludes 1 and Excludes 2 ICD-10-CM Conventions

The Excludes 1 and Excludes 2 ICD-10-CM conventions are crucial for accurate coding assignment. These conventions distinguish between mutually exclusive conditions and those that can coexist.

Excludes 1 Note indicates that two conditions are mutually exclusive and should never be used at the same time as the code above the Excludes1 Note.

Example 1:

Provider reported ICD-10-CM codes R39.15 with N39.41. These two codes should not be reported together.

Denial Rationale: Highmark Wholecare policy, which is based on the Excludes1 Note’s instructions in the ICD-10-CM Official Guidelines for Coding and Reporting.

Example 2:

Provider reported G89.4 and G89.29 together for the same condition, with one code being a more specific version of the other.

Denial Rationale: G89.4 is more descriptive than G89.29. Including both codes on the same claim would trigger an Excludes 1 denial, since only one of these codes should be used to describe the patient’s condition.

Example 3: F11.1 and F11.2 would conflict because F11.2 is a more descriptive version of F11.1, leading to an Excludes 1 denial.

Please Note: The combination of F11.2 and T40.0, while less common, could be relevant in certain cases, such as a patient being both opioid-dependent and experiencing an adverse effect from an underdose of opium.

Excludes 2 Note indicates that the condition excluded is not part of the condition represented by the code, however, the patient may have both conditions. Each condition can be captured and reported separately at the same time.

Example: Patient diagnosed with hypertension and hypertension involving vessels of the brain.

The provider may report I10 and a code from I60-I69 on the same claim because the patient was diagnosed with both conditions.

To learn more about ICD-10-CM coding, reference our on-demand 2025 ICD-10-CM Updates provider webinar.