B26.84 — Mumps polyneuropathy
B26.84 is a billable, specific ICD-10-CM code for mumps polyneuropathy. It is valid for submission on a claim.
Other codes that can never be billed with B26.84
These codes carry an Excludes1 note pointing at B26.84. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading B26.84 alone.
- G63Polyneuropathy in diseases classified elsewhere
Risk adjustment
B26.84 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
B26.84 is named in 3 Medicare coverage policies — 3 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A54095Billing and Coding: Nerve Conduction Studies and Electromyography
- A57123Billing and Coding: Nerve Conduction Studies and Electromyography
- A57204Billing and Coding: MRI and CT Scans of the Head and Neck
How B26.84 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 B26.84.
- Mumps›polyneuropathy
- Polyneuropathy›in›mumps
Related codes at this level
Codes that share B26.8. If B26.84 is not quite right, the correct code is usually one of these.
Questions about B26.84
- Is B26.84 a billable ICD-10-CM code?
- Yes. B26.84 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does B26.84 sit in the tabular list?
- Certain infectious and parasitic diseases (A00-B99), in the block Other viral diseases (B25-B34).