Skip to main content

P91.819 ICD-10-CM Code: Neonatal encephalopathy, unspecified

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Risk adjustment
CMS-HCC V28: 1 category

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 791 — PREMATURITY WITH MAJOR PROBLEMS (MDC 15)
  • MS-DRG 793 — FULL TERM NEONATE WITH MAJOR PROBLEMS (MDC 15)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Risk Adjustment (CMS-HCC)

Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.

  • HCC 202 — Coma, Brain Compression/Anoxic Damage

Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.

Coder workflow for P91.819

MedCoder structured workflow — derived from this code’s own official record

Before you code P91.819

  1. Unspecified does not mean incorrect. When the record gives no greater specificity, P91.819 may be the appropriate code. Check the record for detail that supports a more specific sibling. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).

    ReviewP91.811

    See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

Choose the right path

  1. Does the record document the detail a more specific sibling code needs?
    Yes → Review the specific siblings in this subcategory.
    No → Continue — P91.819 is appropriate when the documentation goes no further.

    ReviewP91.811

Consider P91.819. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Any detail beyond this code’s title
What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: The provider documents the condition in the terms of this code’s title and records no further detail.

Coding question: Is a more specific sibling code supportable?

Path: Review the specific siblings in this subcategory and what each requires the record to state.

Reason: A more specific code needs documentation of the distinguishing element; without it the unspecified code is appropriate, and a provider query is the route to specificity (Guidelines I.A.9.b, I.B.18).

ReviewP91.811

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Neonatal encephalopathy, unspecified is a billable ICD-10-CM diagnosis code (P91.819).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (1)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 2 MS-DRGs: DRG 791 (MDC 15), DRG 793 (MDC 15).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):PNL004 — Neonatal cerebral disorders (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Coma, Brain Compression/Anoxic Damage) for risk-adjusted payment.

P91.1 — Acquired periventricular cysts of newborn, P91.2 — Neonatal cerebral leukomalacia, P91.3 — Neonatal cerebral irritability, P91.4 — Neonatal cerebral depression, P91.5 — Neonatal coma, P91.60 — Hypoxic ischemic encephalopathy [HIE], unspecified, P91.61 — Mild hypoxic ischemic encephalopathy [HIE], P91.62 — Moderate hypoxic ischemic encephalopathy [HIE], P91.63 — Severe hypoxic ischemic encephalopathy [HIE], P91.811 — Neonatal encephalopathy in diseases classified elsewhere, P91.88 — Other specified disturbances of cerebral status of newborn, P91.9 — Disturbance of cerebral status of newborn, unspecified, R40.20 — Unspecified coma, R40.2110 — Coma scale, eyes open, never, unspecified time, R40.2111 — Coma scale, eyes open, never, in the field [EMT or ambulance], R40.2112 — Coma scale, eyes open, never, at arrival to emergency department, R40.2113 — Coma scale, eyes open, never, at hospital admission, R40.2114 — Coma scale, eyes open, never, 24 hours or more after hospital admission, R40.2120 — Coma scale, eyes open, to pain, unspecified time, R40.2121 — Coma scale, eyes open, to pain, in the field [EMT or ambulance], +40 more

Related risk categories

These categories interact through CMS's HCC hierarchy — one can suppress the other's risk-adjustment weight when both are present on a claim.

Major Head Injury with Loss of Consciousness > 1 Hour, Major Head Injury with Loss of Consciousness < 1 Hour or Unspecified, Chronic Liver Failure/End-Stage Liver Disorders

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Neonatal cerebral disorders).

P90 — Convulsions of newborn, P91.0 — Neonatal cerebral ischemia, P91.1 — Acquired periventricular cysts of newborn, P91.2 — Neonatal cerebral leukomalacia, P91.3 — Neonatal cerebral irritability, P91.4 — Neonatal cerebral depression, P91.5 — Neonatal coma, P91.60 — Hypoxic ischemic encephalopathy [HIE], unspecified, P91.61 — Mild hypoxic ischemic encephalopathy [HIE], P91.62 — Moderate hypoxic ischemic encephalopathy [HIE], P91.63 — Severe hypoxic ischemic encephalopathy [HIE], P91.8 — Other specified disturbances of cerebral status of newborn, P91.811 — Neonatal encephalopathy in diseases classified elsewhere, P91.821 — Neonatal cerebral infarction, right side of brain, P91.822 — Neonatal cerebral infarction, left side of brain, P91.823 — Neonatal cerebral infarction, bilateral, P91.829 — Neonatal cerebral infarction, unspecified side, P91.88 — Other specified disturbances of cerebral status of newborn, P91.9 — Disturbance of cerebral status of newborn, unspecified

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Encephalopathy”; these codes share that main term but sit in a different category of the Tabular List.

G31.82 — Leigh's disease (necrotizing, subacute), G32.89 — Other specified degenerative disorders of nervous system in diseases classified elsewhere (degenerative, in specified disease NEC), G37.0 — Diffuse sclerosis of central nervous system (centrolobar progressive), G37.1 — Central demyelination of corpus callosum (demyelinating callosal), G92.8 — Other toxic encephalopathy (due to, drugs), G92.9 — Unspecified toxic encephalopathy (toxic), G93.40 — Encephalopathy, unspecified, G93.41 — Metabolic encephalopathy (septic), G93.45 — Developmental and epileptic encephalopathy (early infantile epileptic), G93.49 — Other encephalopathy (specified NEC), G93.89 — Other specified disorders of brain (postradiation), I67.2 — Cerebral atherosclerosis (arteriosclerotic), I67.4 — Hypertensive encephalopathy (hypertensive), K76.82 — Hepatic encephalopathy (hepatic), P11.1 — Other specified brain damage due to birth injury (in, birth injury), P57.0 — Kernicterus due to isoimmunization (hyperbilirubinemic, newborn, due to isoimmunization), P57.9 — Kernicterus, unspecified (hyperbilirubinemic, newborn), Q07.9 — Congenital malformation of nervous system, unspecified (congenital), QA0.0151 — FOXG1 syndrome (FOXG1-related), T80.69 — Other serum reaction due to other serum (in, serum), +16 more

Contextual Map

Every relationship of P91.819 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Hierarchy

Clinical classification (CCSR)

Risk adjustment (CMS-HCC)

  • HCC 202 — Coma, Brain Compression/Anoxic Damage [CMS-HCC]— CMS-HCC V28 · 2026

MS-DRG Grouper

MDC crossing

Index entries

  • Encephalopathy (acute), neonatal[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (22)

Change history

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Risk adjustment Official source data
2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "P91.819 — Neonatal encephalopathy, unspecified." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/p91.819-neonatal-encephalopathy-unspecified

Change history

  • FY2018 — October 1, 2017
    Added to the code set
    Neonatal encephalopathy, unspecified
    FY2018 changes

Nearest Codes in This Family

Official ICD-10-CM classifications closest to P91.819 in its code family, with their registry titles.

View all codes in the P91 family