ICD-10-CM 2027
ICD-10 code for Monopolar depression
Major depressive disorder, recurrent, unspecified
From the official ICD-10-CM alphabetic index entry “Depression (acute) (mental) › monopolar”. Page updated September 29, 2026.
About coding Monopolar depression
The ICD-10-CM code for Monopolar depression is F33.9 (Major depressive disorder, recurrent, unspecified).
Within F33, choose F33.9 (unspecified) only when documentation doesn't support a more specific option: mild (F33.0), moderate (F33.1), severe without psychotic features (F33.2), severe with psychotic symptoms (F33.3), in remission (F33.4) and other recurrent depressive disorders (F33.8).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 885 (Psychoses, relative weight 1.3901), in MDC 19 (Mental Diseases and Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about Monopolar depression ICD-10 codes
What is the ICD-10 code for Monopolar depression?
- F33.9 — Major depressive disorder, recurrent, unspecified.
Is F33.9 billable?
- Yes. F33.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can F33.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict F33.9 as a principal diagnosis.
Is F33.9 a CC or MCC?
- F33.9 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.