{"code":"Q90.1","type":"code","title":"Trisomy 21, mosaicism (mitotic nondisjunction)","codeAlso":["associated physical condition(s), such as atrioventricular septal defect (Q21.2-)"],"includes":[],"modern_v":"official26","codeFirst":[],"excludes1":[],"excludes2":["mitochondrial metabolic disorders (E88.4-)"],"isBillable":true,"fyEffectivity":{"fy2026":true,"fy2027":true,"billableFy2026":true,"billableFy2027":true},"sibling_codes":["Q90","Q90.0","Q90.2","Q90.9"],"inclusionTerms":[],"sibling_titles":{"code":"Q90.9","title":"Down syndrome, unspecified","isBillable":true},"useAdditionalCode":["code(s) to identify any associated degree of intellectual disabilities (F70-F79)"],"clinicalDefinition":"Trisomy 21, mosaicism (mitotic nondisjunction) is a billable ICD-10-CM diagnosis code (Q90.1). Excludes2 (not included here): mitochondrial metabolic disorders (E88.4-). Use additional code: code(s) to identify any associated degree of intellectual disabilities (F70-F79). Code also: associated physical condition(s), such as atrioventricular septal defect (Q21.2-).","officialDefinition":"Trisomy 21, mosaicism (mitotic nondisjunction) is a billable ICD-10-CM diagnosis code (Q90.1). Excludes2 (not included here): mitochondrial metabolic disorders (E88.4-). Use additional code: code(s) to identify any associated degree of intellectual disabilities (F70-F79). Code also: associated physical condition(s), such as atrioventricular septal defect (Q21.2-).","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":""}