Is D72.821 a billable ICD-10-CM code?

Yes. D72.821 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does D72.821 sit in the tabular list?

Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89), in the block Other disorders of blood and blood-forming organs (D70-D77).

What cannot be coded together with D72.821?

D72.821 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 D72.821 (D72.82, D72.8, D72) and apply to it just the same.

D72.821

D72.821 — Monocytosis (symptomatic)

Billable / specific codeICD-10-CM

D72.821 is a billable, specific ICD-10-CM code for monocytosis (symptomatic). It is valid for submission on a claim.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

infectious mononucleosis (B27.-)

Excludes1 inherited from the categories above D72.821

These are not written on D72.821, but they bind it: a note on a category applies to every code beneath it. Billing D72.821 with anything listed here is a denial.

Written on D72.82 — Elevated white blood cell count

eosinophilia (D72.1)

Written on D72.8 — Other specified disorders of white blood cells

leukemia (C91-C95)

Written on D72 — Other disorders of white blood cells

basophilia (D72.824)
immunity disorders (D80-D89)
preleukemia (syndrome) (D46.9)

Excludes2 inherited from the categories above D72.821

Also inherited, and the opposite of Excludes1: these conditions are not part of D72.821, but a patient can have both, so you may code both.

Written on D72 — Other disorders of white blood cells

neutropenia (D70)

Risk adjustment

D72.821 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

D72.821 is named in 17 Medicare coverage policies — 17 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A55717Billing and Coding: Lab: Flow Cytometry
A56199Billing and Coding: Molecular Pathology Procedures
A56199Billing and Coding: Molecular Pathology Procedures
A56199Billing and Coding: Molecular Pathology Procedures

How D72.821 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 D72.821.

Monocytosis(symptomatic)

Code history

D72.821 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 D72.82. If D72.821 is not quite right, the correct code is usually one of these.

Questions about D72.821

Is D72.821 a billable ICD-10-CM code?: Yes. D72.821 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does D72.821 sit in the tabular list?: Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89), in the block Other disorders of blood and blood-forming organs (D70-D77).
What cannot be coded together with D72.821?: D72.821 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 D72.821 (D72.82, D72.8, D72) and apply to it just the same.