Is R40.4 a billable ICD-10-CM code?

Yes. R40.4 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does R40.4 sit in the tabular list?

Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99), in the block Symptoms and signs involving cognition, perception, emotional state and behavior (R40-R46).

What cannot be coded together with R40.4?

R40.4 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 R40.4 (R40) and apply to it just the same.

R40.4

R40.4 — Transient alteration of awareness

Billable / specific codeICD-10-CM

R40.4 is a billable, specific ICD-10-CM code for transient alteration of awareness. It is valid for submission on a claim.

Excludes1 inherited from the categories above R40.4

These are not written on R40.4, but they bind it: a note on a category applies to every code beneath it. Billing R40.4 with anything listed here is a denial.

Written on R40 — Somnolence, stupor and coma

neonatal coma (P91.5)
somnolence, stupor and coma in diabetes (E08-E13)
somnolence, stupor and coma in hepatic failure (K72.-)
somnolence, stupor and coma in hypoglycemia (nondiabetic) (E15)

Other codes that can never be billed with R40.4

These codes carry an Excludes1 note pointing at R40.4. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading R40.4 alone.

R41.82Altered mental status, unspecified

Risk adjustment

R40.4 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

R40.4 is named in 24 Medicare coverage policies — 24 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A56505Billing and Coding: Transesophageal Echocardiography (TEE)
A56612Billing and Coding: CT of the Head
A56619Billing and Coding: Nerve Conduction Studies and Electromyography
A56625Billing and Coding: Echocardiography

How R40.4 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 R40.4.

Alteration, Altered›awareness›transient

Code history

R40.4 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 R40. If R40.4 is not quite right, the correct code is usually one of these.

Questions about R40.4

Is R40.4 a billable ICD-10-CM code?: Yes. R40.4 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does R40.4 sit in the tabular list?: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99), in the block Symptoms and signs involving cognition, perception, emotional state and behavior (R40-R46).
What cannot be coded together with R40.4?: R40.4 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 R40.4 (R40) and apply to it just the same.