2027 ICD-10-CM Diagnosis Code T78.3XXSAngioneurotic edema, sequela

ICD-10-CM Codes›S00–T88›T66-T78›T78

ICD-10-CM T78.3XXS
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

T78.3XXS is a billable ICD-10-CM diagnosis code for angioneurotic edema, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 922 through 923. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury, sequela.

Code Identity

ICD-10-CM Code
T78.3XXS
Billable Status
Yes — Valid for Submission
Code Describes
Angioneurotic edema, sequela
Short Description
Angioneurotic edema, sequela
Same as the full description in the CMS dataset.
Parent Code
Angioneurotic edema

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT66-T78Other and unspecified effects of external causes
CategoryT78Adverse effects, not elsewhere classified
This CodeT78.3XXSAngioneurotic edema, sequela

Present on Admission (POA)Billing

T78.3XXS is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Other and unspecified effects of external causes (T66-T78).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • ACE inhibitor-aggravated angioedema
  • Acquired angioedema due to C1 inhibitor autoantibody
  • Acquired angioedema due to lymphoproliferative disorder
  • Acquired angioedema type I
  • Acquired angioedema type II
  • Acquired C1 esterase inhibitor deficiency
  • Allergic angioedema
  • Allergic angioedema due to bite and/or sting
  • Allergic angioedema due to ingested food
  • Allergic urticaria and/or angioedema
  • Allergic urticaria caused by ingested food
  • Angioedema
  • Angioedema and/or urticaria
  • Angioedema caused by angiotensin-converting-enzyme inhibitor
  • Angioedema due to disorder of kinin metabolism
  • Angioedema of eyelid
  • Angioedema of lip
  • Angioedema of tongue
  • Angioedema of uvula
  • Aspirin-induced angioedema-urticaria
  • Autoimmune angioedema
  • Autoimmune urticaria and/or angioedema
  • Azo-dye-induced angioedema-urticaria
  • Chemical-aggravated angioedema-urticaria
  • Cholinergic angioedema
  • Cutis laxa following urticaria-angioedema
  • Cutis laxa, acquired type
  • Disorder of eosinophil
  • Drug-aggravated angioedema-urticaria
  • Drug-induced angioedema-urticaria
  • Edema of intestinal tract
  • Edema of oral soft tissues
  • Edema of pharynx
  • Edema of the tongue
  • Edema of uvula
  • Episodic angioedema with eosinophilia
  • Episodic eosinophilia
  • Food-induced angioedema-urticaria
  • Giant urticaria
  • Hevea brasiliensis latex protein-induced angioedema-urticaria
  • Idiopathic angioedema
  • Idiopathic urticaria and/or angioedema
  • Intestinal angioedema caused by angiotensin-converting enzyme inhibitor
  • NSAID -aggravated angioedema-urticaria
  • NSAID-induced angioedema-urticaria
  • Penicillin-induced angioedema-urticaria
  • Physical angioedema
  • Respiratory angioedema
  • Sodium benzoate-induced angioedema-urticaria
  • Urticaria caused by food additive
  • Urticaria caused by salicylate
  • Urticaria medicamentosa
  • Venom-induced angioedema-urticaria
  • Vibratory angioedema

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Adverse effects, not elsewhere classified (T78). Use the following options for the applicable episode of care:

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

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to T78.3XXS: its own notes plus those printed at T78.3, T78, block T66-T78, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From T78.3 Angioneurotic edema applies to 3 codes

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.

From T78 Adverse effects, not elsewhere classified applies to 81 codes
  • complications of surgical and medical care NEC (T80-T88)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

From Block T66-T78 Other and unspecified effects of external causes applies to 456 codes
  • 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-)

Notes

General instructions on how these codes are used.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

From T78 Adverse effects, not elsewhere classified applies to 81 codes
  • The appropriate 7th character is to be added to each code from category T78
  • Ainitial encounter
  • Dsubsequent encounter
  • Ssequela this code

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name T78.3XXS, its category, or a range that includes it.

Excludes1 5

These codes carry an Excludes1 note naming T78.3XXS: they are not reported together with it, unless the two conditions are unrelated.

  • L50 Urticaria
    angioneurotic edema (T78.3) names T78.3, which includes this code
  • L50 Urticaria
    giant urticaria (T78.3) names T78.3, which includes this code
  • L50 Urticaria
    Quincke's edema (T78.3) names T78.3, which includes this code
  • R60 Edema, not elsewhere classified
    angioneurotic edema (T78.3) names T78.3, which includes this code
  • T75 Other and unspecified effects of other external causes
    adverse effects NEC (T78.-) names T78.-, which includes this code

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ073
Injury, sequela
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Angioedema

    swelling involving the deep dermis, subcutaneous, or submucosal tissues, representing localized edema. angioedema often occurs in the face, lips, tongue, and larynx.

Patient EducationClinical

Allergy

An allergy is a reaction by your immune system to something that does not bother most other people. People who have allergies often are sensitive to more than one thing. Substances that often cause reactions are:

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert T78.3XXS to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
909.9 Late eff exter cause NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About T78.3XXSOverview

What is the ICD-10 code for angioneurotic edema, sequela?

The ICD-10-CM code for angioneurotic edema, sequela is T78.3XXS (sometimes written as T783XXS). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is T78.3XXS (Angioneurotic edema) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report angioneurotic edema, sequela on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character S in T78.3XXS mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the angioneurotic edema itself has resolved, not the original event.

What MS-DRG does T78.3XXS group to?

When angioneurotic edema, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 923, 922, with relative weights from 0.9980 to 1.6248 depending on complications. Higher weights mean higher Medicare reimbursement.

Is T78.3XXS 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 angioneurotic edema, sequela on inpatient claims. The code appears in the Other and unspecified effects of external causes (T66-T78) range of the CMS exempt list.