ICD-10 · PDGM grouping
G90 Disorders of autonomic nervous system
All 21 codes in the G90 family, with the PDGM clinical group, comorbidity subgroup and primary-position rule CMS assigns, read from the CMS grouper crosswalk v07.2.26 and the CDC FY2027 code file.
Codes in family
21
Can lead a claim
17
Cannot lead a claim
4
What CMS assigns to G90
17 of the 21 codes group to Neuro Rehabilitation; 4 are assigned no clinical group. Comorbidity subgroups: 1 toward Demyelinating Diseases of the Central Nervous System; 1 toward Nondiabetic neuropathy; 19 are assigned none. 17 of the 21 can lead a claim. CMS attaches a code-first note to 1 of the 21.
- Demyelinating Diseases of the Central Nervous System
- Nondiabetic neuropathy: counts toward the high comorbidity tier only in an interaction pair.
Code first
CMS grouper convention 41, on G90.81. Code first:
- linezolid (T36.8X- with sixth character 1-4)
- monoamine oxidase inhibitors (T43.1X with sixth character 1-4)
- poisoning due to drug or toxin, such as:
- selective serotonin and norepinephrine reuptake inhibitors [SSNRI] (T43.21 with sixth character 1-4)
- selective serotonin reuptake inhibitors [SSRI] (T43.22 with sixth character 1-4)
Every code in G90
Descriptions are CDC’s FY2027 wording; where CMS’s grouper abbreviates one, its form is shown beneath.
| Code | Description | Primary position | Clinical group | Comorbidity subgroup |
|---|---|---|---|---|
| G90.0 Idiopathic peripheral autonomic neuropathy | ||||
| G90.01 | Carotid sinus syncope | Can lead a claim | B | None |
| G90.09 | Other idiopathic peripheral autonomic neuropathy | Can lead a claim | B | Nondiabetic neuropathy |
| G90.1 | Familial dysautonomia [Riley-Day] | Can lead a claim | B | None |
| G90.2 | Horner's syndrome | Can lead a claim | B | None |
| G90.3 | Multi-system degeneration of the autonomic nervous system | Can lead a claim | B | None |
| G90.4 | Autonomic dysreflexia | Can lead a claim | B | None |
| G90.5 Complex regional pain syndrome I (CRPS I) | ||||
| G90.50 | Complex regional pain syndrome I, unspecified | Cannot lead a claimUnspecified diagnosis code not acceptable as principal diagnosis since there is a more specific code available that would further accurately identify the condition | None | None |
| G90.51 Complex regional pain syndrome I of upper limb | ||||
| G90.511 | Complex regional pain syndrome I of right upper limb | Can lead a claim | B | None |
| G90.512 | Complex regional pain syndrome I of left upper limb | Can lead a claim | B | None |
| G90.513 | Complex regional pain syndrome I of upper limb, bilateral | Can lead a claim | B | None |
| G90.519 | Complex regional pain syndrome I of unspecified upper limb | Cannot lead a claimUnspecified diagnosis code not acceptable as principal diagnosis since there is a more specific code available that would further accurately identify the condition | None | None |
| G90.52 Complex regional pain syndrome I of lower limb | ||||
| G90.521 | Complex regional pain syndrome I of right lower limb | Can lead a claim | B | None |
| G90.522 | Complex regional pain syndrome I of left lower limb | Can lead a claim | B | None |
| G90.523 | Complex regional pain syndrome I of lower limb, bilateral | Can lead a claim | B | None |
| G90.529 | Complex regional pain syndrome I of unspecified lower limb | Cannot lead a claimUnspecified diagnosis code not acceptable as principal diagnosis since there is a more specific code available that would further accurately identify the condition | None | None |
| G90.59 | Complex regional pain syndrome I of other specified site | Can lead a claim | B | None |
| G90.8 Other disorders of autonomic nervous system | ||||
| G90.81 | Serotonin syndrome | Can lead a claim, code first applies | B | None |
| G90.89 | Other disorders of autonomic nervous system | Can lead a claim | B | None |
| G90.9 | Disorder of the autonomic nervous system, unspecified | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| G90.A | Postural orthostatic tachycardia syndrome [POTS] | Can lead a claim | B | None |
| G90.B | LMNB1-related autosomal dominant leukodystrophy | Can lead a claim | B | Demyelinating Diseases of the Central Nervous System |
Sources: CMS HH PPS Grouper Software v07.2.26, effective 2026-10-01, for the clinical group, comorbidity subgroup, code-first conventions and primary-position flags; CDC NCHS ICD-10-CM FY2027 code descriptions for the family title and code wording. This is the crosswalk Medicare runs a claim through. Grouping also depends on admission source, timing, the OASIS functional items and the rest of the diagnosis list.
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