2027 ICD-10-CM Diagnosis Code P91.811Neonatal encephalopathy in diseases classified elsewhere
P91.811 is a billable ICD-10-CM diagnosis code for neonatal encephalopathy in diseases classified elsewhere. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 791, 793. The code is a manifestation code that cannot be reported as the principal diagnosis and exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neonatal cerebral disorders.
For Medicare Advantage risk adjustment, P91.811 maps to CMS-HCC Category 202 (Coma, Brain Compression/Anoxic Damage) under the V28 model, adding a risk factor of about 0.543 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for P91.811.
Present on Admission (POA)Billing
P91.811 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Other disorders originating in the perinatal period (P90-P96).
Medicare Risk Adjustment (HCC)Billing
P91.811 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Autoimmune thyroiditis
- Cortical blindness
- Disorder of glutamine metabolism
- Early-onset epileptic encephalopathy, cortical blindness, intellectual disability, facial dysmorphism syndrome
- Hyperglycinemia
- Infantile epileptic dyskinetic encephalopathy
- Infantile glycine encephalopathy
- KCNQ2 developmental and epileptic encephalopathy
- Neonatal epileptic encephalopathy due to glutaminase deficiency
- Neonatal glycine encephalopathy
- Non-ketotic hyperglycinemia
- Steroid-responsive encephalopathy associated with autoimmune thyroiditis
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to P91.811: its own notes plus those printed at Chapter 16. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- conditions that have their origin in the fetal or perinatal period (before birth through the first 28 days after birth) even if morbidity occurs later
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
Code First
The underlying condition named in the note is sequenced before this code.
Notes
General instructions on how these codes are used.
- Codes from this chapter are for use on newborn records only, never on maternal records
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Neonatal Encephalopathy
abnormal functioning of the central nervous system in the newborn period that may be due to a variety of etiologies including hypoxia/ischemia, metabolic disturbance, or infection.
Convert P91.811 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code History & ChangesHistory
Replacement P91.811 replaces the following previously assigned code(s):
- P91.8 - Other specified disturbances of cerebral status of newborn
Questions About P91.811Overview
What is the ICD-10 code for neonatal encephalopathy in diseases classified elsewhere?
The ICD-10-CM code for neonatal encephalopathy in diseases classified elsewhere is P91.811 (sometimes written as P91811). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is P91.811 (Neonatal encephalopathy) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report neonatal encephalopathy in diseases classified elsewhere on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does P91.811 group to?
On inpatient claims, neonatal encephalopathy in diseases classified elsewhere maps to MS-DRG 793, 791, with relative weights from 4.1073 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.
Can P91.811 be a principal diagnosis?
No. This is a manifestation code: neonatal encephalopathy in diseases classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.
Is P91.811 exempt from POA reporting?
Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for neonatal encephalopathy in diseases classified elsewhere on inpatient claims. The code appears in the Other disorders originating in the perinatal period (P90-P96) range of the CMS exempt list.
What HCC is P91.811?
P91.811 (neonatal encephalopathy in diseases classified elsewhere) maps to CMS-HCC Category 202 (Coma, Brain Compression/Anoxic Damage), commonly written as HCC 202, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It does not map to any RxHCC in the Part D prescription drug model.
Does P91.811 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, P91.811 adds a risk adjustment factor of about 0.543 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.097 to 0.721 depending on the payment segment). A more severe related category (HCC 63, HCC 397, and HCC 398) supersedes it when both are reported. See the full factor table on the HCC 202 category page.
