ICD-10-CM tabular list

S00-S09 — Injuries to the head

ICD-10-CM codes S00-S09 cover injuries to the head, within injury, poisoning and certain other consequences of external causes. The block holds 2,690 codes across 10 categories, of which 1,934 are billable and 756 are header codes that cannot be submitted on a claim. 2,690 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)
effects of foreign body in ear (T16)
effects of foreign body in larynx (T17.3)
effects of foreign body in mouth NOS (T18.0)
effects of foreign body in nose (T17.0-T17.1)
effects of foreign body in pharynx (T17.2)
effects of foreign body on external eye (T15.-)
frostbite (T33-T34)
insect bite or sting, venomous (T63.4)

Code also

Both codes may be needed to describe the encounter fully. Sequencing depends on the reason for the visit.

for any associated infection

Includes

Conditions this code covers.

injuries of ear
injuries of eye
injuries of face [any part]
injuries of gum
injuries of jaw
injuries of oral cavity
injuries of palate
injuries of periocular area
injuries of scalp
injuries of temporomandibular joint area
injuries of tongue
injuries of tooth

The 7th character in S00-S09

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. 2,690 of the 2,690 codes here take one.

A: initial encounter
D: subsequent encounter
S: sequela

Risk adjustment in S00-S09

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 399 Major Head Injury without Loss of Consciousness
HCC 397 Major Head Injury with Loss of Consciousness > 1 Hour
HCC 398 Major Head Injury with Loss of Consciousness < 1 Hour or Unspecified

What else to watch in S00-S09

1,038 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.
1,790 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.