F21Schizotypal disorder

F21 is the ICD-10-CM diagnosis code for Schizotypal disorder. It belongs to block F20-F29 (schizophrenia, schizotypal, delusional, and other non-mood psychotic disorders) and chapter 5 (mental, Behavioral and Neurodevelopmental disorders). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

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.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 301.22 (Schizotypal personality disorder).