ICD-10 Codes for PAD & Arterial Ulcers (I70.2-)

The I70.2- severity ladder

ICD-10-CM codes atherosclerotic peripheral artery disease of the legs under I70.2- (native arteries), organized as a ladder of worsening ischemia. The subcategory picks the rung; later characters add laterality and, for ulcers, the site on the leg.

Two boundaries frame the family. Documentation that says only “PAD” or “peripheral vascular disease” — without atherosclerosis — lands on I73.9, whose inclusion terms cover intermittent claudication and peripheral angiopathy NOS; I73.9 carries an Excludes1 for atherosclerosis of the extremities (I70.2- through I70.7-), so the two never appear together. And atherosclerosis in a bypass graft leaves I70.2- entirely: subcategories I70.3- through I70.7- repeat the same ladder for each graft type. One more note worth knowing: category I70 tells you to use an additional code, if applicable, for tobacco use, dependence, or exposure — smoking status is part of the PAD picture.

The codes you'll use most

Need a different site, laterality, or graft code? Search the full I70 family in the lookup tool.

How to choose the right PAD code

1. Confirm what's actually documented

The I70.2- ladder requires atherosclerosis in the note. “PAD,” “PVD,” or “claudication” on their own default to I73.9 — a valid code, but a vague one. If the chart carries imaging or vascular-lab findings of atherosclerotic disease, a quick query moves the claim from I73.9 to the specific ladder. Documentation of chronic limb-threatening ischemia or critical limb ischemia maps into the ladder too: the tabular lists CLTI with rest pain under I70.22-, CLTI with ulceration under I70.23-/I70.24-, and CLTI with gangrene under I70.26-.

2. Take the highest rung — and only that rung

The ladder is cumulative by design, and the tabular says so explicitly. The rest-pain codes include “any condition classifiable to I70.21-”; the ulceration codes include the claudication and rest-pain codes for that leg; and I70.26- (gangrene) includes any condition classifiable to I70.21-, I70.22-, I70.23-, I70.24-, and I70.25. One leg, one I70.2- code, highest rung documented.

3. Add laterality — and the ulcer site

Every rung splits by leg: right, left, and — on every rung except ulceration — bilateral. The ulcer rung trades the bilateral option for site detail — I70.23- is the right leg and I70.24- the left, with the final character naming the site: thigh, calf, ankle, heel and midfoot, other part of foot, or other part of the lower leg. The note has to support that site; an ulcer code with an unspecified site (I70.239, I70.249) is usually one look at the wound-care note away from a better character.

4. Attach the partner codes

The ulcer codes carry a mandatory instruction: use additional code to identify severity of ulcer (L97.-) — the L97 code adds site detail plus depth (breakdown of skin, fat layer exposed, necrosis of muscle or bone). L97 answers back with a code-first note listing atherosclerosis of the lower extremities (I70.23-, I70.24-, and the bypass-graft equivalents), so the I70 code leads and L97 follows. I70.26- takes the ulcer add-on only if applicable (L97.- or L98.49-). Finally, if the record documents a chronic total occlusion of a leg artery, add I70.92 after the I70.2- code — its own code-first note puts the atherosclerosis first.

Common PAD coding mistakes

• Defaulting to I70.209. Unspecified-unspecified is rarely the truth of a vascular note. Laterality and a symptom rung are almost always documented — use them.
• Dropping the L97 severity add-on. I70.23- and I70.24- instruct you to add L97.-; the claim is incomplete without it, and the ulcer's depth lives only in that code.
• Mismatched leg and site. The ulcer subcategories are leg-specific — a left-heel ulcer coded I70.234 (a right-leg code) contradicts the L97 code and the wound-care documentation.
• Reporting I96 with I70.26-. I96 (gangrene, not elsewhere classified) carries an Excludes1 for gangrene in atherosclerosis of the native arteries of the extremities (I70.26-) — the gangrene is already inside the I70 code.
• Missing the diabetes link. In a diabetic patient, PAD is presumed to be diabetic peripheral angiopathy — E11.51/E11.52 belong on the claim (next section), not just the I70 code.

A worked example

The diabetes interlock: E11.51, E11.52, and when to add I70.2-

Many PAD charts are also diabetic charts, and ICD-10-CM links the two automatically. In the Alphabetic Index, peripheral angiopathy sits under “Diabetes, with” — so under the “with” convention the classification presumes a causal relationship: a diabetic patient with PAD is coded to E11.51 (type 2, without gangrene) or E11.52 (with gangrene) — E10.51/E10.52 for type 1 — even without a sentence connecting the two, unless the provider states they're unrelated.

The diabetes codes, though, say nothing about which leg, which site, or how deep. When the note documents atherosclerosis of the native arteries — not just “PAD” — the specific I70.2- code is reported alongside the diabetes combination code: neither code excludes the other, and the I70 code carries the ladder detail the E-code lacks. A documented diabetic foot ulcer without arterial attribution runs through the diabetes family instead: E11.621, whose use-additional note calls for the site and severity from L97.4- or L97.5-. Which chain owns the ulcer — arterial, diabetic, or venous — is a clinical attribution the provider has to make; both diabetic ulcers and atherosclerosis appear in L97's code-first list, so when the note supports more than one etiology and doesn't choose, query rather than guess. The full E11 complication map is in our ICD-10 guide to diabetes codes.

Two neighbors complete the picture. These patients usually carry the rest of the cardiometabolic cluster — the staging and combination rules for kidney disease are in our CKD guide, and BMI-documentation rules in our obesity guide. And don't confuse arterial ulcers with venous ones: an ulcer from chronic venous disease codes through I87.2, I87.3-, or the varicose-vein family instead — see our chronic venous insufficiency guide and varicose veins guide for that side of the boundary.

What the note needs to document

• Atherosclerosis by name — “PAD” alone only supports I73.9
• The highest rung — claudication, rest pain, ulceration, or gangrene — per leg
• For ulcers: which leg, the site, and the depth — feeding both the I70 character and the L97 add-on
• Diabetes status and, when an ulcer is present, its attribution — arterial, diabetic, or mixed

Frequently asked questions