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ICD-10-CM tabular list

S80-S89Injuries to the knee and lower leg

ICD-10-CM codes S80-S89 cover injuries to the knee and lower leg, within injury, poisoning and certain other consequences of external causes. The block holds 5,585 codes across 10 categories, of which 4,680 are billable and 905 are header codes that cannot be submitted on a claim. 5,585 of them (100%) require a 7th character.

Excludes2 — not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

  • burns and corrosions (T20-T32)
  • frostbite (T33-T34)
  • injuries of ankle and foot, except fracture of ankle and malleolus (S90-S99)
  • insect bite or sting, venomous (T63.4)

The 7th character in S80-S89

A code in this block is not complete without its 7th character, and a missing one is a rejected claim rather than a denied one: the clearinghouse never passes it on. 5,585 of the 5,585 codes here take one.

A
initial encounter
D
subsequent encounter
S
sequela

Risk adjustment in S80-S89

0 codes in this block map to a CMS-HCC, which means the diagnosis carries a risk-adjustment payment when it is documented and coded. Under-coding here is money left on the table; over-coding here is what audits are for.

  • HCC 405 Traumatic Amputations and Complications

What else to watch in S80-S89

  • 3,566 codes are laterality-specific. They come in left and right pairs, and the pair is mutually exclusive on a single site: coding both without a bilateral code is a contradiction a scrubber should catch before the payer does.
  • 3,323 codes are named in Medicare coverage policies. An LCD or NCD lists them as supporting medical necessity, or explicitly as not supporting it. Which applies depends on the MAC for your state.

Categories in S80-S89

ICD-10-CMFY2026-Apr· effective April 1, 2026