Question: What’s the diagnosis coding for an aortic root abscess? Florida Subscriber Answer: An aortic root abscess is usually the result of an infection of the aortic valve. If there is no diagnosis indicating an underlying infection, you should request the chart or report be addended to include it so long as the provider agrees. The diagnosis then depends on whether the valve is native or a prosthesis. If the valve is native, you’re left with Infection ? heart ? see Carditis. You may then code via degree of specificity, or report unspecified code I51.89 (Other ill-defined heart diseases). If the valve is prosthetic, you will report code T82.6XXA (Infection and inflammatory reaction due to cardiac valve prosthesis, initial encounter). You’ll then consider the following parent codes: In this case, the additional code to identify the infection will actually be the code you’d report for the native aortic root abscess — I51.89.