ICD-10 Code G93.3 – Postviral and Related Fatigue Syndromes (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G93.3 – Postviral and related fatigue syndromes
What it is
G93.3 identifies postviral and related fatigue syndromes, a group of conditions marked by persistent fatigue after an infection or similar trigger. Use it when the record specifically describes this syndrome rather than general tiredness.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include prolonged fatigue, reduced activity tolerance, and symptoms that continue after the acute illness has resolved.
When to use this code
Use G93.3 when the provider documents postviral fatigue syndrome, myalgic encephalomyelitis, or a related fatigue syndrome. It fits cases where the chart links ongoing fatigue to a prior viral illness or similar postinfectious state. If the note only says fatigue without this diagnosis, check documentation.
Do not use for
Do not use this code for nonspecific weakness, transient tiredness, or fatigue from another clearly documented cause. Check documentation if the record points to depression, anemia, sleep disorder, or another primary explanation.
Coding tip
Code G93.3 only when the clinician names the syndrome or clearly documents a postviral fatigue condition.