2006 ICD-9-CM Volume 1 Diagnosis Codes Home > Diseases Of The Circulatory System 390-459 > Hypertensive Disease 401-405 > Secondary Hypertension 405.* > 2006 ICD-9-CM Diagnosis 405.9 Unspecified secondary hypertension View the most recent version of ICD-9-CM 405.9 405.9 is a non-specific code that cannot be used to specify a diagnosis View the ICD-9-CM Volume 1 405.* hierarchy