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ICD-10/T78.2XXD

T78.2XXD ICD-10-CM Code: Anaphylactic shock, unspecified, subsequent encounter

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

Inpatient Payment Groups (MS-DRG)

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43.0, Appendix B.

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.

Official Registry Overview & Definition

Anaphylactic shock, unspecified, subsequent encounter is a billable ICD-10-CM diagnosis code (T78.2D).

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for T78.2XXD in the official ICD-10-CM tabular list.

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Allergic shock
  • Anaphylactic reaction
  • Anaphylaxis

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Excludes2 — Not Included Here

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

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-)

Change history

No changes recorded for this code — unchanged since the FY2016 baseline of the change ledger.

Verify Before Coding

  • Billable — reportable as written.

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

Contextual Map

Every relationship of T78.2XXD 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

  • T78.2 — Anaphylactic shock, unspecified [Hierarchy]

Referenced by Excludes1 notes

  • T75 — Other and unspecified effects of other external causes [Excludes1](via T78.-): “adverse effects NEC (T78.-)”

Clinical classification (CCSR)

  • INJ067 — Allergic reactions, subsequent encounter [CCSR]

Potential MS-DRG

  • DRG 949 — AFTERCARE WITH CC/MCC [MS-DRG]: “AFTERCARE WITH CC/MCC (MDC 23)”
  • DRG 950 — AFTERCARE WITHOUT CC/MCC [MS-DRG]: “AFTERCARE WITHOUT CC/MCC (MDC 23)”

Nearest codes (40)

  • T78 — Adverse effects, not elsewhere classified [Sibling]
  • T78.119S — Other adverse food reaction due to milk and dairy products with baked milk tolerance/reactivity, unspecified, sequela [Sibling]
  • T78.12 — Other adverse food reaction due to eggs [Sibling]
  • T78.120 — Other adverse food reaction due to egg with tolerance to baked egg [Sibling]
  • T78.120A — Other adverse food reaction due to egg with tolerance to baked egg, initial encounter [Sibling]
  • T78.120D — Other adverse food reaction due to egg with tolerance to baked egg, subsequent encounter [Sibling]
  • T78.120S — Other adverse food reaction due to egg with tolerance to baked egg, sequela [Sibling]
  • T78.121 — Other adverse food reaction due to egg with reactivity to baked egg [Sibling]
  • and 32 more

Referenced by Other Codes

Clinical classification (AHRQ CCSR):INJ067 — Allergic reactions, subsequent encounter (default).

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

Potential MS-DRG Relationships (FY2026)

Not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity.

Named in the grouper logic of 2 MS-DRGs: DRG 949 (MDC 23), DRG 950 (MDC 23).

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

Official ICD-10-CM tabular notes on other codes that name T78.2XXD or its code family.

1 Excludes1 notes: T75 (via T78.-).

Frequently Asked Questions (FAQ) & Clinical Guidance

Does T78.2XXD require a 7th character?

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

Nearest Codes in This Family

Official ICD-10-CM classifications closest to T78.2XXD in its code family, with their registry titles.

  • T78.19XA — Other adverse food reactions, not elsewhere classified, initial encounter
  • T78.19XD — Other adverse food reactions, not elsewhere classified, subsequent encounter
  • T78.19XS — Other adverse food reactions, not elsewhere classified, sequela
  • T78.2 — Anaphylactic shock, unspecified
  • T78.2XXA — Anaphylactic shock, unspecified, initial encounter
  • T78.2XXS — Anaphylactic shock, unspecified, sequela
  • T78.3 — Angioneurotic edema
  • T78.3XXA — Angioneurotic edema, initial encounter
  • T78.3XXD — Angioneurotic edema, subsequent encounter
  • T78.3XXS — Angioneurotic edema, sequela

View all codes in the T78 family