Is R40.0 a billable ICD-10-CM code?

Yes. R40.0 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does R40.0 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 R40.0?

R40.0 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

R40.0

R40.0 — Somnolence

Billable / specific codeICD-10-CM

R40.0 is a billable, specific ICD-10-CM code for somnolence. 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.

coma (R40.2-)

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

Drowsiness

Risk adjustment

R40.0 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

R40.0 is named in 29 Medicare coverage policies — 29 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A54799Billing and Coding: Urine Drug Testing
A55001Billing and Coding: Urine Drug Testing
A56612Billing and Coding: CT of the Head
A56614Billing and Coding: Psychiatric Inpatient Hospitalization

How R40.0 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 R40.0.

Drowsiness
Somnolence

Related codes at this level

Codes that share R40. If R40.0 is not quite right, the correct code is usually one of these.

Questions about R40.0

Is R40.0 a billable ICD-10-CM code?: Yes. R40.0 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does R40.0 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 R40.0?: R40.0 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.