Is Z77.120 a billable ICD-10-CM code?

Yes. Z77.120 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does Z77.120 sit in the tabular list?

Factors influencing health status and contact with health services (Z00-Z99), in the block Persons with potential health hazards related to family and personal history and certain conditions influencing health status (Z77-Z99).

Z77.120

Z77.120 — Contact with and (suspected) exposure to mold (toxic)

Billable / specific codeICD-10-CMPOA exempt

Z77.120 is a billable, specific ICD-10-CM code for contact with and (suspected) exposure to mold (toxic). It is valid for submission on a claim.

Excludes2 inherited from the categories above Z77.120

Also inherited, and the opposite of Excludes1: these conditions are not part of Z77.120, but a patient can have both, so you may code both.

Written on Z77 — Other contact with and (suspected) exposures hazardous to health

contact with and (suspected) exposure to communicable diseases (Z20.-)
exposure to (parental) (environmental) tobacco smoke in the perinatal period (P96.81)
newborn affected by noxious substances transmitted via placenta or breast milk (P04.-)
occupational exposure to risk factors (Z57.-)
retained foreign body (Z18.-)
retained foreign body fully removed (Z87.821)
toxic effects of substances chiefly nonmedicinal as to source (T51-T65)

Other codes that can never be billed with Z77.120

These codes carry an Excludes1 note pointing at Z77.120. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading Z77.120 alone.

Z13.88Encounter for screening for disorder due to exposure to contaminants
Z03Encounter for medical observation for suspected diseases and conditions ruled out

Risk adjustment

Z77.120 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.

How Z77.120 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to Z77.120.

Contact›mold(toxic)
Exposure›mold(toxic)

Code history

Z77.120 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Related codes at this level

Codes that share Z77.12. If Z77.120 is not quite right, the correct code is usually one of these.

Questions about Z77.120

Is Z77.120 a billable ICD-10-CM code?: Yes. Z77.120 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does Z77.120 sit in the tabular list?: Factors influencing health status and contact with health services (Z00-Z99), in the block Persons with potential health hazards related to family and personal history and certain conditions influencing health status (Z77-Z99).