FY2027 ICD-10-CM reference
S04: Injury of cranial nerve
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Injury of cranial nerve. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Nonbillable heading. Verified against the official FY2027 order file.
CMS-HCC V28
Not applicable to this nonbillable heading
CMS-HCC V24
Not applicable to this nonbillable heading
ESRD
Not applicable to this nonbillable heading
PACE
Not applicable to this nonbillable heading
RxHCC
Not applicable to this nonbillable heading
HHS-HCC
Not applicable to this nonbillable heading
More specific FY2027 codes
- S04.0: Injury of optic nerve and pathwaysNonbillable heading
- S04.1: Injury of oculomotor nerveNonbillable heading
- S04.2: Injury of trochlear nerveNonbillable heading
- S04.3: Injury of trigeminal nerveNonbillable heading
- S04.4: Injury of abducent nerveNonbillable heading
- S04.5: Injury of facial nerveNonbillable heading
- S04.6: Injury of acoustic nerveNonbillable heading
- S04.7: Injury of accessory nerveNonbillable heading
- S04.8: Injury of other cranial nervesNonbillable heading
- S04.9: Injury of unspecified cranial nerveNonbillable heading
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Instructional note
Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
Source: S00-T88 (chapter, inherited).
Instructional note
code to identify any retained foreign body, if applicable (Z18.-)
Source: S00-T88 (chapter, inherited).
Excludes2
birth trauma (P10-P15)
Source: S00-T88 (chapter, inherited).
Excludes2
obstetric trauma (O70-O71)
Source: S00-T88 (chapter, inherited).
Instructional note
The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.
Source: S00-T88 (chapter, inherited).
Includes
injuries of ear
Source: S00-S09 (section, inherited).
Includes
injuries of eye
Source: S00-S09 (section, inherited).
Includes
injuries of face [any part]
Source: S00-S09 (section, inherited).
Includes
injuries of gum
Source: S00-S09 (section, inherited).
Includes
injuries of jaw
Source: S00-S09 (section, inherited).
Includes
injuries of oral cavity
Source: S00-S09 (section, inherited).
Includes
injuries of palate
Source: S00-S09 (section, inherited).
Includes
injuries of periocular area
Source: S00-S09 (section, inherited).
Includes
injuries of scalp
Source: S00-S09 (section, inherited).
Includes
injuries of temporomandibular joint area
Source: S00-S09 (section, inherited).
Includes
injuries of tongue
Source: S00-S09 (section, inherited).
Includes
injuries of tooth
Source: S00-S09 (section, inherited).
Code also
for any associated infection
Source: S00-S09 (section, inherited).
Excludes2
burns and corrosions (T20-T32)
Source: S00-S09 (section, inherited).
Excludes2
effects of foreign body in ear (T16)
Source: S00-S09 (section, inherited).
Excludes2
effects of foreign body in larynx (T17.3)
Source: S00-S09 (section, inherited).
Excludes2
effects of foreign body in mouth NOS (T18.0)
Source: S00-S09 (section, inherited).
Excludes2
effects of foreign body in nose (T17.0-T17.1)
Source: S00-S09 (section, inherited).
Excludes2
effects of foreign body in pharynx (T17.2)
Source: S00-S09 (section, inherited).
Excludes2
effects of foreign body on external eye (T15.-)
Source: S00-S09 (section, inherited).
Excludes2
frostbite (T33-T34)
Source: S00-S09 (section, inherited).
Excludes2
insect bite or sting, venomous (T63.4)
Source: S00-S09 (section, inherited).
Instructional note
The selection of side should be based on the side of the body being affected
Source: S04 (category, direct).
Code first
any associated intracranial injury (S06.-)
Source: S04 (category, direct).
Code also
any associated:
Source: S04 (category, direct).
Code also
open wound of head (S01.-)
Source: S04 (category, direct).
Code also
skull fracture (S02.-)
Source: S04 (category, direct).
Seventh-character instruction
The appropriate 7th character is to be added to each code from category S04
Source: S04 (category, direct).
Instructional note
initial encounter
Source: S04 (category, direct).
Instructional note
subsequent encounter
Source: S04 (category, direct).
Instructional note
sequela
Source: S04 (category, direct).
Seventh-character definitions
- A: initial encounter
- D: subsequent encounter
- S: sequela
Compare the FY2027 additions, removals and billable-status changes
What does S04 mean in FY2027?
The official ICD-10-CM descriptor is Injury of cranial nerve. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Is S04 billable in FY2027?
The FY2027 order file marks S04 as a nonbillable heading. Select a complete billable child code.
Does S04 map to an HCC?
Risk-model mapping is not applicable to this nonbillable heading. Check a complete billable child code.
Source: CMS FY2027 ICD-10-CM order file. Payment model: CMS CY 2027 Rate Announcement. Read the FY2027 Official Guidelines.
Review the FY2026 April edition