{"code":"M45.1","type":"code","title":"Ankylosing spondylitis of occipito-atlanto-axial region","codeAlso":[],"includes":[],"modern_v":"official26","codeFirst":[],"excludes1":["arthropathy in Reiter's disease (M02.3-)","juvenile (ankylosing) spondylitis (M08.1)"],"excludes2":["Behçet's disease (M35.2)"],"isBillable":true,"fyEffectivity":{"fy2026":true,"fy2027":true},"sibling_codes":["M45","M45.0","M45.2","M45.3","M45.4","M45.5","M45.6","M45.7","M45.8","M45.9","M45.A","M45.A0","M45.A1","M45.A2","M45.A3","M45.A4","M45.A5","M45.A6","M45.A7","M45.A8","M45.AB"],"inclusionTerms":[],"sibling_titles":{"code":"M45.AB","title":"Non-radiographic axial spondyloarthritis of multiple sites in spine","isBillable":true},"useAdditionalCode":[],"clinicalDefinition":"Ankylosing spondylitis of occipito-atlanto-axial region is a billable ICD-10-CM diagnosis code (M45.1). Excludes1 (not coded here): arthropathy in Reiter's disease (M02.3-); juvenile (ankylosing) spondylitis (M08.1). Excludes2 (not included here): Behçet's disease (M35.2).","officialDefinition":"Ankylosing spondylitis of occipito-atlanto-axial region is a billable ICD-10-CM diagnosis code (M45.1). Excludes1 (not coded here): arthropathy in Reiter's disease (M02.3-); juvenile (ankylosing) spondylitis (M08.1). Excludes2 (not included here): Behçet's disease (M35.2).","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":""}