MCMCB Pro
T78.2

T78.2Anaphylactic shock, unspecified

Non-billable headerICD-10-CM

T78.2 is a non-billable header ICD-10-CM code for anaphylactic shock, unspecified. It cannot be billed on its own: choose one of the more specific child codes below. This code also requires a 7th character before it is complete.

This code requires a 7th character

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

A
initial encounter
D
subsequent encounter
S
sequela

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

  • anaphylactic reaction or shock due to adverse effect of correct medicinal substance properly administered (T88.6)
  • anaphylactic reaction or shock due to adverse food reaction (T78.0-)
  • anaphylactic reaction or shock due to serum (T80.5-)

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Allergic shock
  • Anaphylactic reaction
  • Anaphylaxis

Other codes that can never be billed with T78.2

These codes carry an Excludes1 note pointing at T78.2. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading T78.2 alone.

  • R57Shock, not elsewhere classified
  • T79.4Traumatic shock
  • T79.4XXATraumatic shock, initial encounter
  • T79.4XXDTraumatic shock, subsequent encounter
  • T79.4XXSTraumatic shock, sequela
  • T80.5Anaphylactic reaction due to serum
  • T81.1Postprocedural shock

Risk adjustment

T78.2 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

How T78.2 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to T78.2.

  • Allergy, allergicanaphylactic reaction or shock
  • Allergy, allergicshock(anaphylactic)
  • Shockanaphylactic

Code to one of these instead T78.2

3 child codes. Green means billable.

Related codes at this level

Codes that share T78. If T78.2 is not quite right, the correct code is usually one of these.

Questions about T78.2

Is T78.2 a billable ICD-10-CM code?
No. T78.2 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does T78.2 sit in the tabular list?
Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Other and unspecified effects of external causes (T66-T78).
What cannot be coded together with T78.2?
T78.2 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.