Question: What ICD-10-CM code should I report for Mobitz Block Type 1? I saw this diagnosis in my cardiologist’s documentation, but I have no idea which code to submit. North Carolina Subscriber Answer: You should report I44.1 (Atrioventricular block, second degree) for Mobitz block type I. If you look under included conditions for I44.1, you will see that this code includes types I and II atrioventricular block; types I and II Mobitz block; types I and II second degree block; and Wenckebach’s block. Heart block defined: Heart block or AV block refers to impairment of the electrical signal from the heart’s upper to lower chambers. In a second-degree heart block, some of the signals from the atria don’t reach the ventricles, resulting in a skipped beat (typical of type I) or a slow beat, which may require a pacemaker (typical of type II).