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ICD-10-CM 2027 diagnosis code

G70.1Toxic myoneural disorders

✓ Billable / specific

G70.1 is a valid, billable ICD-10-CM code for toxic myoneural disorders. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About G70.1

G70.1 is the ICD-10-CM diagnosis code for toxic myoneural disorders. It belongs to category G70 (myasthenia gravis and other myoneural disorders), block G70-G73 (diseases of myoneural junction and muscle) and chapter 6 (diseases of the nervous system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within G70 (myasthenia gravis and other myoneural disorders), G70.1 is specifically for toxic myoneural disorders. Related codes cover myasthenia gravis (G70.0), congenital and developmental myasthenia (G70.2), other specified myoneural disorders (G70.8) and myoneural disorder, unspecified (G70.9).

Code first: (T51-T65) to identify toxic agent.

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 073 (Cranial and Peripheral Nerve Disorders with MCC, relative weight 1.5779) and DRG 074 (Cranial and Peripheral Nerve Disorders without MCC, relative weight 1.0173), in MDC 01 (Diseases and Disorders of the Nervous System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 358.2 (toxic myoneural disorders).

Coding notes

Code firstSequence the underlying condition first
  • (T51-T65) to identify toxic agent

Notes that apply from higher levels

Instructions written at a parent level also apply to G70.1.

› From G70 Myasthenia gravis and other myoneural disorders
Excludes1

Broader instructions also apply from Chapter 6: Diseases of the nervous system.

Alphabetic index entries

3 entries

Terms in the official ICD-10-CM index that lead to G70.1.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • 358.2Toxic myoneural disordersexact

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about G70.1

Is G70.1 billable?

Yes. G70.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can G70.1 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict G70.1 as a principal diagnosis.

Is G70.1 a CC or MCC?

No. G70.1 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does G70.1 group to?

G70.1 is used in the MS-DRG v44.0 logic for MS-DRG 073 (Cranial and Peripheral Nerve Disorders with MCC) and MS-DRG 074 (Cranial and Peripheral Nerve Disorders without MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for G70.1?

The CMS General Equivalence Mappings map G70.1 to ICD-9-CM 358.2.