Is Z20.818 a billable ICD-10-CM code?

Yes. Z20.818 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does Z20.818 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 communicable diseases (Z20-Z29).

What cannot be coded together with Z20.818?

Z20.818 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above Z20.818 (Z20) and apply to it just the same.

Z20.818

Z20.818 — Contact with and (suspected) exposure to other bacterial communicable diseases

Billable / specific codeICD-10-CM

Z20.818 is a billable, specific ICD-10-CM code for contact with and (suspected) exposure to other bacterial communicable diseases. It is valid for submission on a claim.

Excludes1 inherited from the categories above Z20.818

These are not written on Z20.818, but they bind it: a note on a category applies to every code beneath it. Billing Z20.818 with anything listed here is a denial.

Written on Z20 — Contact with and (suspected) exposure to communicable diseases

carrier of infectious disease (Z22.-)
diagnosed current infectious or parasitic disease -see Alphabetic Index

Excludes2 inherited from the categories above Z20.818

Also inherited, and the opposite of Excludes1: these conditions are not part of Z20.818, but a patient can have both, so you may code both.

Written on Z20 — Contact with and (suspected) exposure to communicable diseases

personal history of infectious and parasitic diseases (Z86.1-)

Risk adjustment

Z20.818 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 Z20.818 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 Z20.818.

Contact›bacterial disease NEC
Exposure›bacterial disease NEC
Contact›communicable disease›bacterial NEC
Exposure›communicable disease›bacterial NEC

Code history

Z20.818 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 Z20.81. If Z20.818 is not quite right, the correct code is usually one of these.

Questions about Z20.818

Is Z20.818 a billable ICD-10-CM code?: Yes. Z20.818 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does Z20.818 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 communicable diseases (Z20-Z29).
What cannot be coded together with Z20.818?: Z20.818 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above Z20.818 (Z20) and apply to it just the same.