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P35.9 ICD-10-CM Code: Congenital viral disease, unspecified

Compare with another code for P35.9Check this code on a claim

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

Coding at a Glance

Tabular directives
1 inclusion term · 10 Excludes2

Billable · FY2027A valid, specific ICD-10-CM code, reportable for dates of service in FY2027.

What you need to know

Source: CMS/NCHS Official ICD-10-CM tabular notes, quoted. From the CMS/NCHS tabular list for the release in force. A note the category or block publishes applies to this code too, and is marked with where it comes from.

Excludes2Not included here; may be reported together
  • asymptomatic human immunodeficiency virus [HIV] infection status (Z21) (from P35-P39)
  • congenital gonococcal infection (A54.-) (from P35-P39)
  • congenital pneumonia (P23.-) (from P35-P39)
  • congenital syphilis (A50.-) (from P35-P39)

+6 more in Instructions

Includesfrom P35What P35 covers
  • infections acquired in utero or during birth

Where it sits Source: CMS/NCHS

Under:Chapter 16: Certain Conditions Originating in the Perinatal PeriodP35-P39 Infections specific to the perinatal periodP35 Congenital viral diseases

Most relevant related codes MedCoder-derived

Read off the official notes above and this code’s own position in the tabular list. Which to report is a documentation question; Compare shows the two side by side.

CompareCheck ClaimView Related Codes

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 v44, 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.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for P35.9 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Notes without a marker are published on P35.9 itself; “inherited from” names the category or block whose note applies here.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • infections acquired in utero or during birth

Source: inherited from P35

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Coder workflow for P35.9

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

Before you code P35.9

  1. Unspecified does not mean incorrect. When the record gives no greater specificity, P35.9 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).

    ReviewP35.0, P35.1, P35.2, P35.3, P35.4, P35.8

    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 — P35.9 is appropriate when the documentation goes no further.

    ReviewP35.0, P35.1, P35.2, P35.3, P35.4, P35.8

Consider P35.9. 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 code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

  • Excludes2 — not part of P35.9(10 notes)

    Coding workflow: The conditions named in this note are not included in P35.9. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareZ21, A54, P23, A50, B20, A48.51

    See the official tabular notes · Guidelines I.A.12.b

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).

ReviewP35.0, P35.1, P35.2, P35.3, P35.4, P35.8

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.

Don’t confuse P35.9 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of P35.9 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • Z21— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of asymptomatic human immunodeficiency virus [HIV] infection status adds Z21; it is not part of this code and both may be reported when both are documented.

    Full comparison: P35.9 vs Z21 →

  • A54— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of congenital gonococcal infection adds A54; it is not part of this code and both may be reported when both are documented.

    Full comparison: P35.9 vs A54 →

  • P23— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of congenital pneumonia adds P23; it is not part of this code and both may be reported when both are documented.

    Full comparison: P35.9 vs P23 →

  • A50— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of congenital syphilis adds A50; it is not part of this code and both may be reported when both are documented.

    Full comparison: P35.9 vs A50 →

  • B20— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of human immunodeficiency virus [HIV] disease adds B20; it is not part of this code and both may be reported when both are documented.

    Full comparison: P35.9 vs B20 →

  • A48.51— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of infant botulism adds A48.51; it is not part of this code and both may be reported when both are documented.

    Full comparison: P35.9 vs A48.51 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Coding context

Guidelines, coding notes, decision aids, relationships (with MS-DRG and CCSR classification), hierarchy, HCC, coverage and the context map: what a coder reaches for after the core. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Code Overview

Congenital viral disease, unspecified is a billable ICD-10-CM diagnosis code (P35.9).

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

Verify Before Coding

  • MCC as a secondary diagnosis (FY2027). Can raise the stay's MS-DRG severity tier.

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-derived relationships — computed from published CMS and AHRQ datasets

Other codes that name P35.9 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes2 note: P00.2 — Newborn affected by maternal infectious and parasitic diseases (via P35.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: MCC — Major Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 190 clinically related codes on its CMS exclusion list.

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):PNL009 — Perinatal infections (default); INF008 — Viral infection.

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 clinical process (MS-DRG)

Acts as MCC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

M32.13 — Lung involvement in systemic lupus erythematosus, M32.14 — Glomerular disease in systemic lupus erythematosus, M32.15 — Tubulo-interstitial nephropathy in systemic lupus erythematosus, M32.19 — Other organ or system involvement in systemic lupus erythematosus, M32.8 — Other forms of systemic lupus erythematosus, M32.9 — Systemic lupus erythematosus, unspecified, P35.2 — Congenital herpesviral [herpes simplex] infection, P35.3 — Congenital viral hepatitis, P35.4 — Congenital Zika virus disease, P35.8 — Other congenital viral diseases, P37.0 — Congenital tuberculosis, P37.1 — Congenital toxoplasmosis, P37.2 — Neonatal (disseminated) listeriosis, P37.3 — Congenital falciparum malaria, P37.4 — Other congenital malaria, P37.8 — Other specified congenital infectious and parasitic diseases, P37.9 — Congenital infectious or parasitic disease, unspecified, T56.0X1A — Toxic effect of lead and its compounds, accidental (unintentional), initial encounter, T56.0X2A — Toxic effect of lead and its compounds, intentional self-harm, initial encounter, T56.0X3A — Toxic effect of lead and its compounds, assault, initial encounter, +169 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Perinatal infections, Viral infection).

P23.5 — Congenital pneumonia due to Pseudomonas, P23.6 — Congenital pneumonia due to other bacterial agents, P23.8 — Congenital pneumonia due to other organisms, P23.9 — Congenital pneumonia, unspecified, P35.0 — Congenital rubella syndrome, P35.1 — Congenital cytomegalovirus infection, P35.2 — Congenital herpesviral [herpes simplex] infection, P35.3 — Congenital viral hepatitis, P35.4 — Congenital Zika virus disease, P35.8 — Other congenital viral diseases, P36.0 — Sepsis of newborn due to streptococcus, group B, P36.10 — Sepsis of newborn due to unspecified streptococci, P36.19 — Sepsis of newborn due to other streptococci, P36.2 — Sepsis of newborn due to Staphylococcus aureus, P36.30 — Sepsis of newborn due to unspecified staphylococci, P36.39 — Sepsis of newborn due to other staphylococci, P36.4 — Sepsis of newborn due to Escherichia coli, P36.5 — Sepsis of newborn due to anaerobes, P36.8 — Other bacterial sepsis of newborn, P36.9 — Bacterial sepsis of newborn, unspecified, +360 more

Contextual Map

Every relationship of P35.9 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.

Run P35.9 with this related code in Claim Check

Hierarchy

Referenced by Excludes2 notes

Clinical classification (CCSR)

MS-DRG Grouper

  • MCC — Major Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (MCC).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2027
  • DRG 791 — PREMATURITY WITH MAJOR PROBLEMS[MS-DRG]: “PREMATURITY WITH MAJOR PROBLEMS (MDC 15)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2027
  • DRG 793 — FULL TERM NEONATE WITH MAJOR PROBLEMS[MS-DRG]: “FULL TERM NEONATE WITH MAJOR PROBLEMS (MDC 15)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2027

MDC crossing

Index entries

  • Disease, diseased, infectious, infective, congenital, viral[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Disease, diseased, viral, virus, congenital[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Infection, infected, infective (opportunistic), congenital, virus[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027

Nearest codes

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Reference

Index terms and tables, published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.

Indexed Clinical Terms (3)

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.

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 FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 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 — v44 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-derived 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 editorial 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.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 28, 2026 · All releases and sources

Labels on this page: Official source data · MedCoder-derived relationship · MedCoder editorial explanation. How to read the labels · All data sources and release dates · CMS coding rules

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. "P35.9 — Congenital viral disease, unspecified." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/p35.9-congenital-viral-disease-unspecified

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Congenital viral disease, unspecified

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to P35.9 in its code family, with their registry titles.

View all codes in the P35 family