S02.109A Fracture of base of skull, unspecified side, initial encounter for closed fracture

Billable ICD-10-CM code, FY2026.

Built from S02.109 with 7th character A (initial encounter for closed fracture).

Applies from S02 Fracture of skull and facial bones

Code also

• any associated intracranial injury (S06.-)

7th character note

• The appropriate 7th character is to be added to each code from category S02

Notes

• A fracture not indicated as open or closed should be coded to closed

7th character required

• A — initial encounter for closed fracture
• B — initial encounter for open fracture
• D — subsequent encounter for fracture with routine healing
• G — subsequent encounter for fracture with delayed healing
• K — subsequent encounter for fracture with nonunion
• S — sequela

Applies from S02.1 Fracture of base of skull

Excludes2 (not included here)

• lateral orbital wall (S02.84-)
• medial orbital wall (S02.83-)
• orbital floor (S02.3-)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 399 — Major Head Injury without Loss of Consciousness
• CMS-HCC V22: HCC 167 — Major Head Injury
• ESRD V24: HCC 167

Medicare Code Edits (MCE v43.1 (April 2026))

• Unspecified code (laterality): Unspecified codes for which a more specific code identifying laterality (right, left, bilateral) exists within the same code family.

Code annotations containing back-references to S02.109A

Back-references to S02.1

• Type 2 Excludes: S02.3 Fracture of orbital floor ("orbital roof (S02.1-)")
• Type 2 Excludes: S05 Injury of eye and orbit ("orbital bone fracture (S02.1-, S02.3-, S02.8-)")

Back-references to S02

• Code Also: G96.00 Cerebrospinal fluid leak, unspecified ("head injury (S00-S09)")
• Code Also: G96.08 Other cranial cerebrospinal fluid leak ("head injury (S00 - S09)")
• Code Also: G96.09 Other spinal cerebrospinal fluid leak ("head injury (S00 - S09)")
• Code First: R40.2 Coma ("fracture of skull (S02.-)")
• Type 1 Excludes: S01 Open wound of head ("open skull fracture (S02.- with 7th character B)")
• Code Also: S04 Injury of cranial nerve ("skull fracture (S02.-)")
• Code Also: S06 Intracranial injury ("skull fracture (S02.-)")
• Use Additional: S07 Crushing injury of head ("skull fractures (S02.-)")

Nearby codes

• S02.102D Fracture of base of skull, left side, subsequent encounter for fracture with routine healing
• S02.102G Fracture of base of skull, left side, subsequent encounter for fracture with delayed healing
• S02.102K Fracture of base of skull, left side, subsequent encounter for fracture with nonunion
• S02.102S Fracture of base of skull, left side, sequela
• S02.109 Fracture of base of skull, unspecified side
• S02.109A Fracture of base of skull, unspecified side, initial encounter for closed fracture (this code)
• S02.109B Fracture of base of skull, unspecified side, initial encounter for open fracture
• S02.109D Fracture of base of skull, unspecified side, subsequent encounter for fracture with routine healing
• S02.109G Fracture of base of skull, unspecified side, subsequent encounter for fracture with delayed healing
• S02.109K Fracture of base of skull, unspecified side, subsequent encounter for fracture with nonunion
• S02.109S Fracture of base of skull, unspecified side, sequela