Is S99 a billable ICD-10-CM code?

No. S99 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does S99 sit in the tabular list?

Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Injuries to the ankle and foot (S90-S99).

S99

S99 — Other and unspecified injuries of ankle and foot

Non-billable headerICD-10-CMunspecified

S99 is a non-billable header ICD-10-CM code for other and unspecified injuries of ankle and foot. It cannot be billed on its own: choose one of the more specific child codes below.

Risk adjustment

S99 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code to one of these instead S99

5 child codes. Green means billable.

S99.0Physeal fracture of calcaneus
S99.1Physeal fracture of metatarsal
S99.2Physeal fracture of phalanx of toe
S99.8Other specified injuries of ankle and foot
S99.9Unspecified injury of ankle and foot

Questions about S99

Is S99 a billable ICD-10-CM code?: No. S99 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does S99 sit in the tabular list?: Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Injuries to the ankle and foot (S90-S99).