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T78.01 ICD-10-CM Code: Anaphylactic reaction due to peanuts

Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.

Coding at a Glance

7th character
Required — see the character table on this page
Tabular directives
1 Excludes2 · 6 code-also instructions

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for T78.01 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 T78.01 itself; “inherited from” names the category or block whose note applies here.

Excludes2 — Not Included Here

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

Source: inherited from T78

Code Also

Additional codes that may be required to fully describe the encounter.

  • Code also, if applicable, place of occurrence, such as:
  • highway rest stop (Y92.523)
  • school (private) (public) (state) as the place of occurrence of the external cause (Y92.21-)
  • service areas as the place of occurrence of the external cause (Y92.52-)
  • single-family non-institutional (private) house as the place of occurrence of the external cause (Y92.01-)
  • transport vehicle as the place of occurrence of the external cause (Y92.81-)

Source: inherited from T66-T78

7th Character Guide

"The appropriate 7th character is to be added to each code from category T78"

  • A — initial encounter
  • D — subsequent encounter
  • S — sequela

How the encounter character is assigned. “Initial encounter” means the patient is receiving active treatment for the condition — it is not limited to the first visit, and a different or new provider giving active treatment still assigns it. “Subsequent encounter” covers care during the healing or recovery phase after active treatment. “Sequela” is for complications or conditions that arise as a direct result of the original condition.

ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.19.a (paraphrased by MedCoder).

Variant codes in this family

T78.01XA, T78.01XD, T78.01XS

Character meanings are CMS's official 7th-character extensions for this family, as carried in each variant code's official description; variant codes are registry rows. The explanation of how the encounter character is assigned is MedCoder editorial, distinct from the official content above it.

Coder workflow for T78.01

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

Before you code T78.01

  1. T78.01 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).

    ReviewT78.01XA, T78.01XD, T78.01XS

    See the relationships section · Guide: How to choose an ICD-10-CM code →

  2. A 7th character is required in this family. Confirm the documented encounter: initial (active treatment), subsequent (healing or recovery phase), or sequela. T78.01 is not valid without one. “Initial” means active treatment, not the first visit (Guidelines I.C.19.a).

    See the 7th Character Guide · Guide: 7th characters: initial, subsequent, sequela →

  3. T78.01’s title joins a condition with an associated condition or complication. Confirm each component is documented. Where the classification presumes the link through the “with” convention, only a provider statement that the conditions are unrelated defeats it. A combination code is assigned only when it fully identifies the documented conditions; a required second code for the stage, type or manifestation is still reported when the notes ask for it (Guidelines I.B.9, I.A.15).

    Guide: Combination codes →

Choose the right path

  1. Does the documentation support one of the more specific codes beneath T78.01?
    Yes → Select that code and continue the checks below on its own page.
    No → T78.01 cannot be reported as written; query for the specificity its subcategory needs.

    ReviewT78.01XA, T78.01XD, T78.01XS

  2. Is the encounter phase documented — active treatment, healing or recovery, or a sequela?
    Yes → Assign the matching 7th character; the variant codes are in the 7th Character Guide.
    No → The code is invalid without its 7th character — query for the missing element.

Consider T78.01. Then review the Code Also note, and 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).
Encounter type
Active treatment, healing or recovery phase, or sequela — the basis of the 7th character (Guidelines I.C.19.a).
The associated condition or complication
Whether the associated condition the title names is documented; the “with” convention presumes some links, and a provider statement that the conditions are unrelated defeats it (Guidelines I.A.15).

Official instructions as workflow

  • Excludes2 — not part of T78.01(1 note)

    Coding workflow: The conditions named in this note are not included in T78.01. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

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

  • Code Also — related condition(6 notes)

    Coding workflow: Review the related condition when both are documented and the instruction applies. A Code Also note does not fix sequencing; the order follows the circumstances of the encounter.

    ReviewY92.523, Y92.21, Y92.52, Y92.01, Y92.81

    See the official tabular notes · Guidelines I.A.17

Coding decision scenarios

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

Documentation: The patient returns during the healing or recovery phase after active treatment of the same condition.

Coding question: Which 7th character applies?

Path: Review the official 7th-character definitions for this family in the 7th Character Guide.

Reason: “Initial encounter” means active treatment, not the first visit; care during recovery takes “subsequent encounter”, and a complication arising from the original condition takes “sequela” (Guidelines I.C.19.a).

Documentation: Only one of the components this code’s title joins is documented.

Coding question: Is T78.01 supported?

Path: Review the code for the documented component on its own.

Reason: A combination code is assigned only when it fully identifies the documented conditions; otherwise the documented component takes its own code (Guidelines I.B.9).

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 T78.01 with…

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

The codes most likely to be picked instead of T78.01 — 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.

  • T78.00— Specificity relationship (Review)

    Overlapping diagnoses in the same category.

    Overlapping codes in the same category — the documentation decides which is the more specific fit.

    What moves you there: A record that documents no more than “Anaphylactic reaction due to unspecified food” takes T78.00; specificity in the record moves it back here.

    Full comparison: T78.01 vs T78.00 →

  • T78.01XA— Encounter relationship (Review)

    Same underlying diagnosis, different encounter phase.

    The same diagnosis at a different phase of care; one encounter takes one 7th character.

    What moves you there: Documentation of a initial encounter moves the case to T78.01XA.

    Full comparison: T78.01 vs T78.01XA →

  • T78.01XD— Encounter relationship (Review)

    Same underlying diagnosis, different encounter phase.

    The same diagnosis at a different phase of care; one encounter takes one 7th character.

    What moves you there: Documentation of a subsequent encounter moves the case to T78.01XD.

    Full comparison: T78.01 vs T78.01XD →

  • T80— 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 complications of surgical and medical care NEC adds T80; it is not part of this code and both may be reported when both are documented.

    Full comparison: T78.01 vs T80 →

  • T88— 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 complications of surgical and medical care NEC adds T88; it is not part of this code and both may be reported when both are documented.

    Full comparison: T78.01 vs T88 →

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.

Code Overview

Anaphylactic reaction due to peanuts is a non-billable ICD-10-CM category code (T78.01). A more specific billable subcode must be selected for claims submission.

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 (2)

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.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

  1. A 7th character applies in this family. Confirm the documented encounter matches the character assigned. See the official 7th-character definitions and this code’s variants
  2. 6 Code Also notes — a second code may apply; the guidelines leave its sequencing to the circumstances of the encounter. See the Code Also notes
  3. 1 Excludes2 entry — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

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

Other codes that name T78.01 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 8 Excludes1 notes across 2 chapters: R57 — Shock, not elsewhere classified (via T78.0.-), T61 — Toxic effect of noxious substances eaten as seafood (via T78.0.-), T62 — Toxic effect of other noxious substances eaten as food (via T78.0.-), T75 — Other and unspecified effects of other external causes (via T78.-), T78.1 — Other adverse food reactions, not elsewhere classified (via T78.0.-), T78.2 — Anaphylactic shock, unspecified (via T78.0.-), T79.4 — Traumatic shock (via T78.0.-), T88.6 — Anaphylactic reaction due to adverse effect of correct drug or medicament properly administered (via T78.0.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 2 Excludes2 notes across 2 chapters: L27 — Dermatitis due to substances taken internally (via T78.-), T78.05 — Anaphylactic reaction due to tree nuts and seeds.

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

Related Codes

Same Index main term, other category

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

N17.0 — Acute kidney failure with tubular necrosis (kidney), O08.3 — Shock following ectopic and molar pregnancy (with ectopic or molar pregnancy), O75.1 — Shock during or following labor and delivery (obstetric), R57.0 — Cardiogenic shock (cardiogenic), R57.1 — Hypovolemic shock (hypovolemic), R57.8 — Other shock (hemorrhagic), R57.9 — Shock, unspecified, R65.21 — Severe sepsis with septic shock (septic), T75.01 — Shock due to being struck by lightning (lightning), T75.4 — Electrocution (electric), T79.4 — Traumatic shock (traumatic), T79.5 — Traumatic anuria (kidney, traumatic), T80.51 — Anaphylactic reaction due to administration of blood and blood products (anaphylactic, serum, blood and blood products), T80.52 — Anaphylactic reaction due to vaccination (anaphylactic, immunization), T80.59 — Anaphylactic reaction due to other serum (anaphylactic, serum), T81.10 — Postprocedural shock unspecified (surgical), T81.11 — Postprocedural cardiogenic shock (postprocedural, cardiogenic), T81.12 — Postprocedural septic shock (postprocedural, septic), T81.19 — Other postprocedural shock (pleural), T88.2 — Shock due to anesthesia (anesthetic, correct substance properly administered), +7 more

Contextual Map

Every relationship of T78.01 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 T78.01 with these 10 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes

Referenced by Excludes2 notes

Index entries

  • Shock, anaphylactic, due to food (nonpoisonous), nuts, peanuts[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Shock, anaphylactic, due to food (nonpoisonous), peanuts[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (40)

Change history

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

Common coding questions

Can T78.01 be billed directly?

No. T78.01 (Anaphylactic reaction due to peanuts) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

Does T78.01 require a 7th character?

Yes. The appropriate 7th character is to be added to each code from category T78.

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
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. "T78.01 — Anaphylactic reaction due to peanuts." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/t78.01-anaphylactic-reaction-due-to-peanuts

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Anaphylactic reaction due to peanuts

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 T78.01 in its code family, with their registry titles.

View all codes in the T78 family