{"code":"D89.41","type":"code","title":"Monoclonal mast cell activation syndrome","codeAlso":[],"includes":["defects in the complement system","immunodeficiency disorders, except human immunodeficiency virus [HIV] disease","sarcoidosis"],"modern_v":"official26","codeFirst":[],"excludes1":["aggressive systemic mastocytosis (C96.21)","congenital cutaneous mastocytosis (Q82.2)","(non-congenital) cutaneous mastocytosis (D47.01)","(indolent) systemic mastocytosis (D47.02)","malignant mast cell neoplasm (C96.2-)","malignant mastocytoma (C96.29)","mast cell leukemia (C94.3-)","mast cell sarcoma (C96.22)","mastocytoma NOS (D47.09)","other mast cell neoplasms of uncertain behavior (D47.09)","systemic mastocytosis associated with a clonal hematologic non-mast cell lineage disease (SM-AHNMD) (D47.02)","hyperglobulinemia NOS (R77.1)","monoclonal gammopathy (of undetermined significance) (D47.2)","autoimmune disease (systemic) NOS (M35.9)","functional disorders of polymorphonuclear neutrophils (D71-)"],"excludes2":["transplant failure and rejection (T86.-)","human immunodeficiency virus [HIV] disease (B20)"],"isBillable":true,"fyEffectivity":{"fy2026":true,"fy2027":true,"billableFy2026":true,"billableFy2027":true},"inclusionTerms":[],"useAdditionalCode":[],"clinicalDefinition":"Monoclonal mast cell activation syndrome is a billable ICD-10-CM diagnosis code (D89.41). Includes: defects in the complement system; immunodeficiency disorders, except human immunodeficiency virus [HIV] disease; sarcoidosis. Excludes1 (not coded here): aggressive systemic mastocytosis (C96.21); congenital cutaneous mastocytosis (Q82.2); (non-congenital) cutaneous mastocytosis (D47.01); (indolent) systemic mastocytosis (D47.02); malignant mast cell neoplasm (C96.2-); malignant mastocytoma (C96.","officialDefinition":"Monoclonal mast cell activation syndrome is a billable ICD-10-CM diagnosis code (D89.41). Includes: defects in the complement system; immunodeficiency disorders, except human immunodeficiency virus [HIV] disease; sarcoidosis. Excludes1 (not coded here): aggressive systemic mastocytosis (C96.21); congenital cutaneous mastocytosis (Q82.2); (non-congenital) cutaneous mastocytosis (D47.01); (indolent) systemic mastocytosis (D47.02); malignant mast cell neoplasm (C96.2-); malignant mastocytoma (C96.29); mast cell leukemia (C94.3-); mast cell sarcoma (C96.22); mastocytoma NOS (D47.09); other mast cell neoplasms of uncertain behavior (D47.09); systemic mastocytosis associated with a clonal hematologic non-mast cell lineage disease (SM-AHNMD) (D47.02); hyperglobulinemia NOS (R77.1); monoclonal gammopathy (of undetermined significance) (D47.2); autoimmune disease (systemic) NOS (M35.9); functional disorders of polymorphonuclear neutrophils (D71-); human immunodeficiency virus [HIV] disease (B20). Excludes2 (not included here): transplant failure and rejection (T86.-).","seventhCharacterInstructions":[],"workflowProtocols":[],"guidelines":{"whenToUse":[],"whenNotToUse":[],"commonBillingMistakes":[],"codeComparisons":[],"documentationChecklist":[]},"domainLandscape":{"summary":"Primary diagnostic domain and clinical landscape evaluation.","keyCategories":[],"diagnosticContinuum":"Progression continuum from acute presentation to resolution."},"children":[],"hierarchy":[],"relatedCodes":[],"relevantCPTCodes":[],"documentationTips":[],"caseStudies":[],"description":"","overview":""}