Is A51.3 a billable ICD-10-CM code?

No. A51.3 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does A51.3 sit in the tabular list?

Certain infectious and parasitic diseases (A00-B99), in the block Infections with a predominantly sexual mode of transmission (A50-A64).

A51.3

A51.3 — Secondary syphilis of skin and mucous membranes

Non-billable headerICD-10-CM

A51.3 is a non-billable header ICD-10-CM code for secondary syphilis of skin and mucous membranes. It cannot be billed on its own: choose one of the more specific child codes below.

Other codes that can never be billed with A51.3

These codes carry an Excludes1 note pointing at A51.3. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading A51.3 alone.

A52.79Other symptomatic late syphilis
L99Other disorders of skin and subcutaneous tissue in diseases classified elsewhere

Risk adjustment

A51.3 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 A51.3

3 child codes. Green means billable.

Related codes at this level

Codes that share A51. If A51.3 is not quite right, the correct code is usually one of these.

Questions about A51.3

Is A51.3 a billable ICD-10-CM code?: No. A51.3 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does A51.3 sit in the tabular list?: Certain infectious and parasitic diseases (A00-B99), in the block Infections with a predominantly sexual mode of transmission (A50-A64).