Is S21.05 a billable ICD-10-CM code?

No. S21.05 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does S21.05 sit in the tabular list?

Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Injuries to the thorax (S20-S29).

What cannot be coded together with S21.05?

S21.05 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

S21.05

S21.05 — Open bite of breast

Non-billable headerICD-10-CM

S21.05 is a non-billable header ICD-10-CM code for open bite of breast. It cannot be billed on its own: choose one of the more specific child codes below. This code also requires a 7th character before it is complete.

This code requires a 7th character

The appropriate 7th character is to be added to each code from category S21

A: initial encounter
D: subsequent encounter
S: sequela

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

superficial bite of breast (S20.17)

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

Bite of breast NOS

Other codes that can never be billed with S21.05

These codes carry an Excludes1 note pointing at S21.05. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading S21.05 alone.

S20.17Other superficial bite of breast

Risk adjustment

S21.05 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 S21.05

3 child codes. Green means billable.

Related codes at this level

Codes that share S21.0. If S21.05 is not quite right, the correct code is usually one of these.

Questions about S21.05

Is S21.05 a billable ICD-10-CM code?: No. S21.05 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does S21.05 sit in the tabular list?: Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Injuries to the thorax (S20-S29).
What cannot be coded together with S21.05?: S21.05 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.