---
title: "ICD-10-CM G56.42: Causalgia of left upper limb | BillingBrief"
description: "ICD-10-CM code G56.42: Causalgia of left upper limb. Category, related codes, and the official source, in plain English."
canonical: "https://billingbrief.com/icd10/g56.42/"
language: "en"
---

# G56.42 Causalgia of left upper limb

ICD-10-CM · [CMS code reference](#source)

**Official ICD-10-CM description:** Causalgia of left upper limb

## Coding notes

From the ICD-10-CM FY2027 (effective October 1, 2026) tabular list. Notes on a parent code or category apply here too.

### Excludes1

Not coded together with this code. The exception is when the two conditions are unrelated to each other.

-   complex regional pain syndrome I of lower limb (G90.52-)
-   complex regional pain syndrome I of upper limb (G90.51-)
-   complex regional pain syndrome II of lower limb (G57.7-)
-   reflex sympathetic dystrophy of lower limb (G90.52-)
-   reflex sympathetic dystrophy of upper limb (G90.51-)
-   current traumatic nerve disorder - see nerve injury by body region
-   current traumatic nerve, nerve root and plexus disorders - see Injury, nerve by body region
-   neuralgia NOS ([M79.2](https://billingbrief.com/icd10/m79.2/))
-   neuritis NOS ([M79.2](https://billingbrief.com/icd10/m79.2/))
-   peripheral neuritis in pregnancy (O26.82-)
-   radiculitis NOS (M54.1-)

## Related codes

-   [`G56.32` Lesion of radial nerve, left upper limb ICD-10-CM](https://billingbrief.com/icd10/g56.32/)
-   [`G56.33` Lesion of radial nerve, bilateral upper limbs ICD-10-CM](https://billingbrief.com/icd10/g56.33/)
-   [`G56.40` Causalgia of unspecified upper limb ICD-10-CM](https://billingbrief.com/icd10/g56.40/)
-   [`G56.41` Causalgia of right upper limb ICD-10-CM](https://billingbrief.com/icd10/g56.41/)
-   [`G56.43` Causalgia of bilateral upper limbs ICD-10-CM](https://billingbrief.com/icd10/g56.43/)
-   [`G56.80` Other specified mononeuropathies of unspecified upper limb ICD-10-CM](https://billingbrief.com/icd10/g56.80/)
-   [`G56.81` Other specified mononeuropathies of right upper limb ICD-10-CM](https://billingbrief.com/icd10/g56.81/)
-   [`G56.82` Other specified mononeuropathies of left upper limb ICD-10-CM](https://billingbrief.com/icd10/g56.82/)

## Common questions

### Is G56.42 a billable code?

Yes. G56.42 is a billable ICD-10-CM code in the ICD-10-CM FY2027 (effective October 1, 2026) code set.

## From the source

Official description from [CMS](https://www.cms.gov/medicare/coding-billing/icd-10-codes).
ICD-10-CM FY2027 (effective October 1, 2026).

Code set

ICD-10-CM

Category

G56 Mononeuropathies of upper limb

Chapter

Diseases of the nervous system

Billable

Yes

Educational reference only. Not medical, legal, or billing advice. Always check the current official code set and payer policy before you bill. [About BillingBrief and our sources](https://billingbrief.com/about/).