Overview When coding a patient’s mental health diagnosis, it’s essential to follow ICD-10-CM Official Guidelines to ensure claims are accurate and compliant. One common issue arises when a major depressive disorder (MDD) code is reported alongside a bipolar disorder code, which can lead to claim denials due to Excludes1 conflicts.
The Problem: Bipolar and MDD Codes Together
Often claims are denied because they include both:
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F31.81 – Bipolar II disorder, and
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F32.2 – Major depressive disorder, single episode, severe
This combination is not allowed under ICD-10 rules. According to the ICD-10 Excludes1 note, MDD codes (F32.x, F33.x) should not be reported with bipolar disorder codes (F31.x) because:
Depressive episodes are already inherent in bipolar disorder and should be coded within the bipolar category, not as a separate MDD diagnosis.
Correct Coding: Bipolar Depression
When a patient with bipolar disorder is experiencing a depressive episode, choose the appropriate bipolar code that reflects the current mood state.
Bipolar II Disorder:
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F31.81 – Bipolar II disorder
→ This includes major depressive episodes by definition.
→ Do not pair this with F32.x or F33.x codes.
Bipolar I Disorder with Depressive Episode:
Use one of the following, depending on severity and features:
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F31.31 – Bipolar I, current episode depressed, mild
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F31.32 – Bipolar I, current episode depressed, moderate
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F31.4 – Bipolar I, current episode depressed, severe, without psychotic features
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F31.5 – Bipolar I, current episode depressed, severe, with psychotic features
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F31.75/F31.76 – In remission (partial/full), most recent episode depressed
Additional Tips
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Always document the type of bipolar disorder (I vs. II) and the current mood episode.
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Avoid using F32.x (single episode MDD) or F33.x (recurrent MDD) in any patient diagnosed with bipolar disorder.
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If you’re unsure, refer to the Excludes1 notes in the ICD-10 codebook