ICD-10-CM 2027
ICD-10 code for borderline schizophrenia
From the official ICD-10-CM alphabetic index entry “Schizophrenia, schizophrenic › borderline”. Page updated September 29, 2026.
About coding borderline schizophrenia
The ICD-10-CM code for borderline schizophrenia is F21 (Schizotypal disorder).
The conditions in its Excludes2 note aren't part of F21, but may be coded alongside it if the patient has both: Asperger's syndrome (F84.5) and schizoid personality disorder (F60.1).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 883 (Disorders of Personality and Impulse Control, relative weight 1.7697), 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 borderline schizophrenia ICD-10 codes
What is the ICD-10 code for borderline schizophrenia?
- F21 — Schizotypal disorder.
Is F21 billable?
- Yes. F21 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can F21 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict F21 as a principal diagnosis.
Is F21 a CC or MCC?
- No. F21 is neither a CC nor an MCC under MS-DRG v44.0.