Q:  There’s an assumed cause and effect relationship between diabetes and peripheral artery disease, but what about coronary artery disease?  Do we make the link between CAD and diabetes?​
A:  No.  Diabetes has a causal relationship with peripheral vascular disease.  There is no assumed relationship between diabetes and CAD and the conditions are coded separately.​

Q:  Why would you not add a code for diabetic foot ulcer if the patient has diabetes, arteriosclerotic PVD, and a foot ulcer?  Don’t you need that code for specificity?​
A:  When a patient has a foot ulcer with arteriosclerotic PVD and diabetes, multiple coding conventions apply.  Arteriosclerosis is a specific type of angiopathy.  ICD-10-CM assumes a cause and effect relationship between diabetes and angiopathy (arteriosclerosis).  ICD-10-CM also assumes a link between arteriosclerosis and the foot ulcer and tabular instructions direct the coder to use an additional code for non-pressure ulcer to describe the site and depth of the ulceration.  The combination of these codes provide all the detail to know that the patient has diabetes and an ulcer.  The code for diabetic foot ulcer does not provide any additional detail.​

Q:  There’s an assumed cause and effect relationship between diabetes and peripheral artery disease, but what about coronary artery disease?  Do we make the link between CAD and diabetes?
A:  No.  Diabetes has a causal relationship with peripheral vascular disease.  There is no assumed relationship between diabetes and CAD and the conditions are coded separately.

Q:  Why would you not add a code for diabetic foot ulcer if the patient has diabetes, arteriosclerotic PVD, and a foot ulcer?  Don’t you need that code for specificity?
A:  When a patient has a foot ulcer with arteriosclerotic PVD and diabetes, multiple coding conventions apply.  Arteriosclerosis is a specific type of angiopathy.  ICD-10-CM assumes a cause and effect relationship between diabetes and angiopathy (arteriosclerosis).  ICD-10-CM also assumes a link between arteriosclerosis and the foot ulcer and tabular instructions direct the coder to use an additional code for non-pressure ulcer to describe the site and depth of the ulceration.  The combination of these codes provide all the detail to know that the patient has diabetes and an ulcer.  The code for diabetic foot ulcer does not provide any additional detail.

Q:  I am looking for guidance regarding coding CAD with HTN. I have been linking the 2 diagnoses: I25.10, Atherosclerotic heart disease of native coronary artery without angina pectoris and I11.9, Hypertensive heart disease without heart failure. Is this the correct way to code or should I use I25.10 & I10?
A:  CAD (I25.-) is not listed as one of the linked conditions under category I11 for hypertensive heart disease.  An assumed link is only made between hypertension and codes classified to I50.-, I51.4-, I51.7, I51.89, or I51.9.  See the includes notes under code I11 and coding guideline I.C.9.a.1. for further clarification.

Q:  Does peripheral neuropathy w/DM code to polyneuropathy?
A:  Peripheral neuropathy is damage to the nerves outside of the brain and spinal cord.  When multiple peripheral nerves are affected, it is referred to as polyneuropathy.  When the provider documents diabetic peripheral neuropathy, assign a code for unspecified diabetic neuropathy (e.g., E11.40, Type 2 diabetes mellitus with diabetic neuropathy, unspecified) unless the documentation indicates that multiple nerves were affected.  If, for example, the provider documented that a type 2 diabetic had peripheral neuropathy in both legs, code E11.42, Type 2 diabetes mellitus with diabetic polyneuropathy, would be assigned.