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ICD-10-CM 2027 diagnosis code

T78.080SAnaphylactic reaction due to egg with tolerance to baked egg, sequela

✓ Billable / specificPOA exemptRequires 7th character

T78.080S is a valid, billable ICD-10-CM code for anaphylactic reaction due to egg with tolerance to baked egg, sequela. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Anaphyl react due to egg with tolerance to baked egg, sqla

Code last changed in FY2026 (effective October 1, 2025). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About T78.080S

T78.080S is the ICD-10-CM diagnosis code for anaphylactic reaction due to egg with tolerance to baked egg, sequela. It belongs to category T78 (adverse effects, not elsewhere classified), block T66-T78 (other and unspecified effects of external causes) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

The 7th character "S" means sequela: use it for complications or conditions that arise as a direct result of the original condition.

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 922 (Other Injury, Poisoning and Toxic Effect Diagnoses with MCC, relative weight 1.6238) and DRG 923 (Other Injury, Poisoning and Toxic Effect Diagnoses without MCC, relative weight 0.9973), in MDC 21 (Injuries, Poisonings and Toxic Effects of Drugs), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is exempt from present-on-admission (POA) reporting, so no POA indicator is required.

It was added in FY2026, effective October 1, 2025.

7th character

Ssequela

CC/MCC status for this injury by encounter: CC for A; Neither CC nor MCC for D, S.

Other encounter types for T78.080:

Notes that apply from higher levels

Instructions written at a parent level also apply to T78.080S.

› From T78.080 Anaphylactic reaction due to egg with tolerance to baked egg
Excludes1
  • Anaphylactic reaction due to egg with reactivity to baked egg (T78.081)
› From T78 Adverse effects, not elsewhere classified
Excludes2
  • complications of surgical and medical care NEC (T80-T88)

Broader instructions also apply from T66-T78 Other and unspecified effects of external causes and Chapter 19: Injury, poisoning and certain other consequences of external causes.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2026 (effective 10/1/2025): Added
  • No changes since FY2026.

Common questions about T78.080S

Is T78.080S billable?

Yes. T78.080S is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

What does the "S" at the end of T78.080S mean?

It is the 7th character for sequela. Per the official guidelines, use it for complications or conditions that arise as a direct result of the original condition.

Can T78.080S be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict T78.080S as a principal diagnosis.

Is T78.080S a CC or MCC?

No. T78.080S is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does T78.080S group to?

T78.080S is used in the MS-DRG v44.0 logic for MS-DRG 922 (Other Injury, Poisoning and Toxic Effect Diagnoses with MCC) and MS-DRG 923 (Other Injury, Poisoning and Toxic Effect Diagnoses without MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.