ICD-10 Code B27.11 – Cytomegaloviral mononucleosis with polyneuropathy (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B27.11 – Cytomegaloviral mononucleosis with polyneuropathy
What it is
This code identifies infectious mononucleosis caused by cytomegalovirus, with associated polyneuropathy. Use it when the record documents both the CMV mononucleosis and nerve involvement affecting multiple peripheral nerves.
Clinical signs
Typical findings include a mononucleosis-like illness plus evidence of peripheral neuropathy, such as numbness, tingling, weakness, or reduced reflexes. Clinical features vary; refer to documentation.
When to use this code
Use B27.11 when the provider clearly documents cytomegaloviral mononucleosis and specifies polyneuropathy as a related manifestation. It may also apply when the diagnosis is confirmed in the assessment, discharge summary, or problem list.
Do not assign it for CMV infection without mononucleosis, or for mononucleosis without documented polyneuropathy. Check documentation if the nerve findings are described only as neuropathy, neuritis, or weakness without a clear link.
Do not use for
Do not use this code for Epstein-Barr virus mononucleosis, unspecified CMV disease, or isolated peripheral neuropathy. If the chart does not confirm both conditions, code the documented diagnosis instead.
Coding tip
Verify that the provider links polyneuropathy to cytomegaloviral mononucleosis before assigning B27.11.