Billable ICD-10 Code for Stable Bipolar I Disorder
For a patient with stable bipolar I disorder currently in remission, the appropriate billable ICD-10 code is F31.70 (Bipolar disorder, currently in remission, most recent episode unspecified) or more specifically F31.71, F31.72, F31.73, F31.74, F31.75, or F31.76 depending on the most recent episode type (hypomanic, manic, depressed, mixed, or unspecified).
Understanding the ICD-10 Coding Structure for Bipolar I
The F31 category encompasses all bipolar affective disorder diagnoses, with the fourth and fifth digits specifying the current clinical state and most recent episode type 1, 2.
F31.7x codes specifically indicate "currently in remission," which is the appropriate designation for stable patients who are symptom-free or have minimal residual symptoms while maintained on treatment 1, 2.
The sixth digit (0-6) specifies the most recent episode: 0=unspecified, 1=hypomanic, 2=manic, 3=depressed, 4=mixed, 5=in partial remission, 6=in full remission 2.
Most Commonly Used Codes for Stable Bipolar I
F31.76 (Bipolar disorder, in full remission, most recent episode mixed) is frequently used when the patient has achieved complete symptom resolution 2.
F31.75 (Bipolar disorder, in partial remission, most recent episode depressed) applies when minimal residual symptoms persist but the patient is functionally stable 2.
F31.70 (Bipolar disorder, currently in remission, most recent episode unspecified) can be used when the specific episode type is not documented or relevant 2.
Clinical Documentation Requirements
Documentation should specify that the patient is currently stable, maintained on mood stabilizers (such as lithium, valproate, or lamotrigine) and/or antipsychotics, and is adherent to treatment 1, 2.
The medical record should note the most recent episode type (manic, hypomanic, depressed, or mixed) to support the sixth-digit code selection 2.
Maintenance therapy typically continues for at least 12-24 months after achieving stability, with some patients requiring lifelong treatment 1, 3.
Important Coding Considerations
The "in remission" designation does not mean the patient is off medication—most stable bipolar I patients remain on maintenance pharmacotherapy indefinitely due to high relapse risk 1, 2, 4.
Withdrawal of maintenance therapy is associated with relapse rates exceeding 90% in noncompliant patients versus 37.5% in compliant patients 1.
Avoid using acute episode codes (F31.0-F31.6) for stable patients, as these indicate current symptomatic episodes requiring active intervention 2.
Common Documentation Pitfalls
Failing to specify the most recent episode type results in defaulting to F31.70 (unspecified), which provides less clinical information for continuity of care 2.
Using "unspecified bipolar disorder" (F31.9) is inappropriate for diagnosed bipolar I patients with documented history, even when stable 2.
Documenting only "bipolar disorder" without specifying current status may lead to incorrect coding of an active episode when the patient is actually stable 2, 3.