ICD-10 Code for Head Injury

Also searched as head trauma

Head injury is coded S09.90- — Unspecified injury of head. A 7th character for the encounter is required before it can be billed. Valid for FY2027.

S09.90 not billable7th character required

Head injury ICD-10 codes at a glance

ConditionHead injury
CodeS09.90-Unspecified injury of head
BillableNo — S09.90 is a header; use a code beneath it
Alphabetic Index entryInjury, head
Code setICD-10-CM FY2027, valid October 1, 2026 – September 30, 2027

Which 7th character does a head injury code need?

Every head injury code requires a 7th character describing the encounter. For S09.90- the options are:

Ainitial encounterS09.90XA
Dsubsequent encounterS09.90XD
SsequelaS09.90XS

What changes the head injury code?

The Alphabetic Index lists these qualifiers under Injury, head. If the record documents one of them, the code changes. Verify the code in the Tabular List before reporting it.

with loss of consciousnessS06.9-Unspecified intracranial injury
specified NECS09.8-Other specified injuries of head

What does the Tabular List say about S09.90?

The instructional notes that govern S09.90-, including those it inherits from its category and chapter. An Excludes1 note means the two codes are never reported together.

Excludes1 — never code together

The conditions below can never be reported together with S09.90 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.

  • brain injury NOS (S06.9-)
  • head injury NOS with loss of consciousness (S06.9-)
  • intracranial injury NOS (S06.9-)

Inclusion terms

Alternative wording in documentation that is classified to S09.90.

  • Head injury NOS

Use additional code — inherited from Chapter 19

Report an additional code alongside S09.90 to fully describe the condition. S09.90 is sequenced first.

  • code to identify any retained foreign body, if applicable (Z18.-)

Excludes2 — not included here — inherited from Chapter 19

The conditions below are not part of S09.90, but a patient may have both at the same time. When documentation supports it, S09.90 and the excluded code may both be reported.

  • birth trauma (P10-P15)
  • obstetric trauma (O70-O71)

Excludes2 — not included here — inherited from S00-S09

The conditions below are not part of S09.90, but a patient may have both at the same time. When documentation supports it, S09.90 and the excluded code may both be reported.

  • 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 — inherited from S00-S09

Two codes may be needed to describe the condition fully. Whether S09.90 is sequenced first depends on the reason for the encounter.

  • for any associated infection

Codes, descriptions and Index entries are from the official ICD-10-CM FY2027 release. Guideline text is quoted from the ICD-10-CM Official Guidelines for Coding and Reporting FY 2027. A code must always be verified in the Tabular List before it is reported. Data sources