Is Q99 a billable ICD-10-CM code?

No. Q99 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does Q99 sit in the tabular list?

Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0), in the block Chromosomal abnormalities, not elsewhere classified (Q90-Q99).

Q99

Q99 — Other chromosome abnormalities, not elsewhere classified

Non-billable headerICD-10-CM

Q99 is a non-billable header ICD-10-CM code for other chromosome abnormalities, not elsewhere classified. It cannot be billed on its own: choose one of the more specific child codes below.

Other codes that can never be billed with Q99

These codes carry an Excludes1 note pointing at Q99. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading Q99 alone.

Q56Indeterminate sex and pseudohermaphroditism
R62Lack of expected normal physiological development in childhood and adults
Z15Genetic susceptibility to disease
E28.3Primary ovarian failure
E25Adrenogenital disorders

Risk adjustment

Q99 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 Q99

5 child codes. Green means billable.

Questions about Q99

Is Q99 a billable ICD-10-CM code?: No. Q99 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does Q99 sit in the tabular list?: Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0), in the block Chromosomal abnormalities, not elsewhere classified (Q90-Q99).