ICD-10 Code D89.3 – Immune reconstitution syndrome (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D89.3 – Immune reconstitution syndrome
What it is
Immune reconstitution syndrome is an inflammatory response that can appear after immune function begins to recover, often in people with severe immunosuppression. You use this code when the documentation identifies this specific syndrome.
Clinical signs
Clinical features vary; refer to documentation. Typical notes describe a new or worsening inflammatory reaction after immune recovery, sometimes with symptoms that reflect a prior infection becoming clinically apparent.
When to use this code
Use D89.3 when the provider documents immune reconstitution syndrome, immune reconstitution inflammatory syndrome, or an equivalent diagnosis. It may be reported when symptoms emerge after immune recovery and the record links them to this condition. Check documentation for the underlying disease and timing.
Do not use for
Do not assign this code for uncomplicated infection, general inflammation, or immune suppression without reconstitution syndrome. If the chart only mentions possible immune recovery effects, check documentation.
Coding tip
Code the syndrome only when the provider clearly documents it; also capture any associated underlying condition if instructed by the record.