2008 ICD-9-CM Volume 1 Diagnosis Codes Home > Diseases Of The Respiratory System 460-519 > Chronic Obstructive Pulmonary Disease And Allied Conditions 490-496 > Chronic Bronchitis 491.* > 2008 ICD-9-CM Diagnosis 491.2 Obstructive chronic bronchitis  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 Therefore, this code may be out of date.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 491.2 can be accessed here. 491.2 is a non-specific code that cannot be used to specify a diagnosis View the ICD-9-CM Volume 1 491.* hierarchy ICD9Data's sister site ProcedureCodes.com launches with the 2008/09 CPT® codes - read more on the ICD9Data.com blog. 491.2 also known as: Bronchitis: emphysematous obstructive (chronic) (diffuse) Bronchitis with: chronic airway obstruction emphysema 491.2 excludes: asthmatic bronchitis (acute) (NOS) 493.9 chronic obstructive asthma 493.2