G73.1 — Lambert-Eaton syndrome in neoplastic disease
Is G73.1 billable?
Yes — G73.1 is billable for FY2027. G73.1 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. G73.1 may be submitted for encounters from October 1, 2026 through September 30, 2027.
G73.1 at a glance
| Code | G73.1 |
|---|---|
| Description | Lambert-Eaton syndrome in neoplastic disease |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
What Medicare edits apply to G73.1?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name G73.1 directly.
This code describes a manifestation of an underlying disease. The underlying condition must be sequenced before it, so it can never be the principal or first-listed diagnosis.
CMS will reject this code as the principal diagnosis on an inpatient claim. It describes something other than the condition chiefly responsible for the admission.
Which MS-DRGs does G73.1 group to?
G73.1 sits in MDC 01 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 056Degenerative Nervous System Disorders with MCCmedical
- 057Degenerative Nervous System Disorders without MCCmedical
As a secondary diagnosis, G73.1 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is G73.1 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to G73.1. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Syndrome › Lambert-Eaton › in › neoplastic disease
Excludes1 — never code together
The conditions below can never be reported together with G73.1 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- Lambert-Eaton syndrome not associated with neoplasm (G70.80-G70.81)
Code first
The underlying condition below must be sequenced before G73.1. G73.1 describes a manifestation and cannot be the principal or first-listed diagnosis.
- underlying neoplasm (C00-D49)
Excludes2 — not included here — inherited from Chapter 6
The conditions below are not part of G73.1, but a patient may have both at the same time. When documentation supports it, G73.1 and the excluded code may both be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
How long has G73.1 existed?
G73.1 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.