O99.331 ICD-10-CM Code: Smoking (tobacco) complicating pregnancy, first trimester
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FY 2026 Apr update / Pregnancy, childbirth and the puerperium (O00-O9A) / Other obstetric conditions, not elsewhere classified (O94-O9A)
O99.331
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceSmoking (tobacco) complicating pregnancy, first trimester
Tobacco smoking during the first three months of pregnancy (first trimester) that causes complications for the mother or fetus.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
N/A—
Not mapped
ACA/HHS
MappedHCC 212
Varies by metal level
ESRD/PACE
N/A—
Not mapped
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
Official- Smoking complicating pregnancy, childbirth, and the puerperium
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for O99.331 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for O99.331 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for O99.331 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for O99.331 in this effective period.
Use Additional
Official- code from category F17 to identify type of tobacco nicotine dependence
Code Also
OfficialICD-10-CM does not list Code Also instructions for O99.331 in this effective period.
Buddy Documentation Tip
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is O99.331 an HCC code?
No. O99.331 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
- Code
- O99.331
- Description
- Smoking (tobacco) complicating pregnancy, first trimester
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF
- —
- Billable
- Yes
- Payment year
- 2026
Coder workflow notes
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This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
O99.331 is the ICD-10-CM diagnosis code for smoking (tobacco) complicating pregnancy, first trimester. Tobacco smoking during the first three months of pregnancy (first trimester) that causes complications for the mother or fetus. O99.331 sits in the ICD-10-CM chapter for pregnancy, childbirth and the puerperium (o00-o9a), within the section covering other obstetric conditions, not elsewhere classified (o94-o9a).
O99.331 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
Confirm first trimester timing is documented before assigning this code.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for O99.331 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm first trimester timing is documented before assigning this code
- •Document smoking quantity and any documented effects on early fetal development