Non-Billable / Non-Specific Code
ICD-10-CM R40.21 is the diagnosis code for Coma scale, eyes open. This code falls under the section "Symptoms and signs involving cognition, perception, emotional state and behavior" within Chapter 18 — Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99). It is a non-billable/non-specific ICD-10-CM code that should not be used for reimbursement. A more specific sub-code is required for billing. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.
Always refer to the official ICD-10-CM Tabular List for complete coding guidelines. Ensure documentation supports the specificity of the code selected. When in doubt, consult a certified medical coder or the latest CMS guidelines.
Understanding where R40.21 sits in the ICD-10-CM classification helps ensure proper coding:
No, R40.21 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.
R40.21 is the ICD-10-CM diagnosis code for "Coma scale, eyes open". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
The parent code of R40.21 is R40.2 ("Coma"). R40.21 provides a more specific classification within this category.
R40.21 is located in Section R40-R46 — "Symptoms and signs involving cognition, perception, emotional state and behavior" within Chapter 18 of the ICD-10-CM Tabular List.
R40.21 has 4 sub-code(s) that provide more specific detail: R40.211, R40.212, R40.213, R40.214.
Use R40.21 when the patients documented diagnosis matches "Coma scale, eyes open" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Coma scale, eyes open is R40.21.
No, R40.21 is non-billable. Use a more specific sub-code for primary diagnosis billing.
R40.21 is in Chapter 18 of the ICD-10-CM Tabular List.
Yes, R40.21 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.