G31.84 — Mild cognitive impairment of uncertain or unknown etiology
Is G31.84 billable?
Yes — G31.84 is billable for FY2027. G31.84 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. G31.84 may be submitted for encounters from October 1, 2026 through September 30, 2027.
G31.84 at a glance
| Code | G31.84 |
|---|---|
| Description | Mild cognitive impairment of uncertain or unknown etiology |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does G31.84 group to?
G31.84 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
How is G31.84 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to G31.84. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Disorder › mild neurocognitive (of)
- Impaired, impairment › cognitive, mild, of uncertain or unknown etiology (function)
- Impaired, impairment › mild cognitive (function)
- Disorder › neurocognitive › mild (of)
- Impaired, impairment › mild cognitive › of uncertain or unknown etiology (function)
Excludes1 — never code together
The conditions below can never be reported together with G31.84 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- age related cognitive decline (R41.81)
- altered mental status (R41.82)
- cerebral degeneration (G31.9)
- cerebrovascular diseases (I60-I69)
- change in mental status (R41.82)
- cognitive deficits following (sequelae of) cerebral hemorrhage or infarction (I69.01-, I69.11-, I69.21-, I69.31-, I69.81-, I69.91-)
- cognitive impairment due to intracranial or head injury (S06.-)
- dementia (F01.-, F02.-, F03.-)
- mild neurocognitive disorder due to a known physiological condition (F06.7-)
- neurologic neglect syndrome (R41.4)
- personality change, nonpsychotic (F68.8)
Use additional code
Report an additional code alongside G31.84 to fully describe the condition. G31.84 is sequenced first.
Inclusion terms
Alternative wording in documentation that is classified to G31.84.
- Mild cognitive disorder NOS
- Mild neurocognitive disorder of uncertain or unknown etiology
Use additional code — inherited from G31
Report an additional code alongside G31.84 to fully describe the condition. G31.84 is sequenced first.
- code, if applicable, for codes G31.0-G31.83, G31.85-G31.9, to identify:
- dementia with anxiety (F02.84, F02.A4, F02.B4, F02.C4)
- dementia with behavioral disturbance (F02.81-, F02.A1-, F02.B1-, F02.C1-)
- dementia with mood disturbance (F02.83, F02.A3, F02.B3, F02.C3)
- dementia with psychotic disturbance (F02.82, F02.A2, F02.B2, F02.C2)
- dementia without behavioral disturbance (F02.80, F02.A0, F02.B0, F02.C0)
- mild neurocognitive disorder due to known physiological condition (F06.7-)
Excludes2 — not included here — inherited from Chapter 6
The conditions below are not part of G31.84, but a patient may have both at the same time. When documentation supports it, G31.84 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)
Excludes2 — not included here — inherited from G31
The conditions below are not part of G31.84, but a patient may have both at the same time. When documentation supports it, G31.84 and the excluded code may both be reported.
- Reye's syndrome (G93.7)
How long has G31.84 existed?
G31.84 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
- FY2023Mild cognitive impairment, so statedMild cognitive impairment of uncertain or unknown etiology
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.