2006 ICD-9-CM Volume 1 Diagnosis Codes > Diseases Of The Respiratory System 460-519 > Chronic Obstructive Pulmonary Disease And Allied Conditions 490-496 > 490 Bronchitis not specified as acute or chronic 491 Chronic bronchitis 492 Emphysema 493 Asthma 494 Bronchiectasis 495 Extrinsic allergic alveolitis 496 Chronic airway obstruction not elsewhere classified