Is O99.321 a billable ICD-10-CM code?

Yes. O99.321 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does O99.321 sit in the tabular list?

Pregnancy, childbirth and the puerperium (O00-O9A), in the block Other obstetric conditions, not elsewhere classified (O94-O9A).

O99.321

O99.321 — Drug use complicating pregnancy, first trimester

Billable / specific codeICD-10-CM

O99.321 is a billable, specific ICD-10-CM code for drug use complicating pregnancy, first trimester. It is valid for submission on a claim.

Risk adjustment

O99.321 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.

Medicare coverage

O99.321 is named in 1 Medicare coverage policy — 1 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A57189Billing and Coding: Serum Magnesium

Related codes at this level

Codes that share O99.32. If O99.321 is not quite right, the correct code is usually one of these.

Questions about O99.321

Is O99.321 a billable ICD-10-CM code?: Yes. O99.321 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does O99.321 sit in the tabular list?: Pregnancy, childbirth and the puerperium (O00-O9A), in the block Other obstetric conditions, not elsewhere classified (O94-O9A).