I70.9Other and unspecified atherosclerosis

I70.9 is the ICD-10-CM diagnosis code for other and unspecified atherosclerosis. It belongs to category I70 (atherosclerosis), block I70-I79 (diseases of arteries, arterioles and capillaries) and chapter 9 (diseases of the circulatory system). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

Within I70, choose I70.9 (Other and unspecified atherosclerosis) only when documentation doesn't support a more specific option: of aorta (I70.0), of renal artery (I70.1), of native arteries of the extremities (I70.2), of unspecified type of bypass graft(s) of the extremities (I70.3), of autologous vein bypass graft(s) of the extremities (I70.4), of nonautologous biological bypass graft(s) of the extremities (I70.5), of nonbiological bypass graft(s) of the extremities (I70.6), of other type of bypass graft(s) of the extremities (I70.7) and 1 more.

To report this condition, pick the subcode that matches the documentation: I70.90 (atherosclerosis), I70.91 (atherosclerosis) and I70.92 (extremities).

The conditions in its Excludes2 note aren't part of I70.9, but may be coded alongside it if the patient has both: disorders of pyrophosphate metabolism (E83.82-).

Use an additional code to identify: exposure to environmental tobacco smoke (Z77.22), history of tobacco dependence (Z87.891), occupational exposure to environmental tobacco smoke (Z57.31), tobacco dependence (F17.-) and tobacco use (Z72.0).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.