ICD-10-CM 2027
ICD-10 code for Nostalgia
From the official ICD-10-CM alphabetic index entry “Nostalgia”. Page updated September 29, 2026.
About coding Nostalgia
The ICD-10-CM code for Nostalgia is F43.20 (Adjustment disorder, unspecified).
Within F43.2, choose F43.20 (disorder, unspecified) only when documentation doesn't support a more specific option: disorder with depressed mood (F43.21), disorder with anxiety (F43.22), disorder with mixed anxiety and depressed mood (F43.23), disorder with disturbance of conduct (F43.24), disorder with mixed disturbance of emotions and conduct (F43.25) and disorder with other symptoms (F43.29).
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 882 (Neuroses Except Depressive, relative weight 0.9952), 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 Nostalgia ICD-10 codes
What is the ICD-10 code for Nostalgia?
- F43.20 — Adjustment disorder, unspecified.
Is F43.20 billable?
- Yes. F43.20 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can F43.20 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict F43.20 as a principal diagnosis.
Is F43.20 a CC or MCC?
- No. F43.20 is neither a CC nor an MCC under MS-DRG v44.0.