2008 ICD-9-CM Volume 1 Diagnosis Codes Home > Symptoms, Signs, And Ill-Defined Conditions 780-799 > Ill-Defined And Unknown Causes Of Morbidity And Mortality 797-799 > Other Ill-Defined And Unknown Causes Of Morbidity And Mortality 799.* > 2008 ICD-9-CM Diagnosis 799.9 Other unknown and unspecified cause of morbidity or mortality  On October 1, 2008 the 2009 ICD-9-CM codes came into effect. Therefore, this code may be out of date. The 2009 version of ICD-9-CM 799.9 can be accessed here. 799.9 is a specific code that can be used to specify a diagnosis 799.9 contains 12 index entries View the ICD-9-CM Volume 1 799.* hierarchy ICD9Data's sister site ProcedureCodes.com launches with the 2008/09 CPT® codes - read more on the ICD9Data.com blog. 799.9 also known as: Undiagnosed disease, not specified as to site or system involved Unknown cause of morbidity or mortality Index entries containing 799.9: Cause not stated 799.9 unknown 799.9 Diagnosis deferred 799.9 Disease, diseased - see also Syndrome undiagnosed 799.9 No diagnosis 799.9 Sick 799.9 cilia syndrome 759.89 or handicapped person in family V61.49 Surgical operation NEC 799.9 Undetermined diagnosis or cause 799.9 Undiagnosed (disease) 799.9 Unknown cause of death 799.9 diagnosis 799.9 Unspecified cause of death 799.9