DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

Category · FY2027

T78 Adverse effects, not elsewhere classified

  • Header · not billable
  • Codes take a 7th character

T78 is not billable. The category heads 81 billable codes in FY2027, grouped under 6 subdivisions. Its codes take a 7th character, so none is complete with fewer than 7 characters.

Index → code

  • Bannister's disease → T78.3
  • Quincke's disease or edema → T78.3
  • Arthus' phenomenon or reaction → T78.41

Where it sits

  1. Chapter 19 Injury, poisoning and certain other consequences of external causes (S00-T88)
  2. T66-T78 Other and unspecified effects of external causes (T66-T78)
  3. T78 Adverse effects, not elsewhere classified
Billable codes
81
Subdivisions
6
CC / MCC codes
15 / 0
HCC V28 codes
0
New FY2027
0
Index entries
72

Codes in T78

  1. T78.0
    Anaphylactic reaction due to food
    Header
    Inclusion terms 3

    Inclusion terms

    • Anaphylactic reaction due to adverse food reaction
    • Anaphylactic shock or reaction due to nonpoisonous foods
    • Anaphylactoid reaction due to food
  2. T78.00
    Anaphylactic reaction due to unspecified food +7th: A D S
    Needs 7th characterCC AExempt: 2 of 3 7th characters
  3. T78.01
    Anaphylactic reaction due to peanuts +7th: A D S
    Needs 7th characterCC AExempt: 2 of 3 7th characters
  4. T78.02
    Anaphylactic reaction due to shellfish (crustaceans) +7th: A D S
    Needs 7th characterCC AExempt: 2 of 3 7th characters
  5. T78.03
    Anaphylactic reaction due to other fish +7th: A D S
    Needs 7th characterCC AExempt: 2 of 3 7th characters
  6. T78.04
    Anaphylactic reaction due to fruits and vegetables +7th: A D S
    Needs 7th characterCC AExempt: 2 of 3 7th characters
  7. T78.05
    Anaphylactic reaction due to tree nuts and seeds +7th: A D S
    Needs 7th characterCC AExempt: 2 of 3 7th characters
    Excludes2 1

    Excludes2

    • anaphylactic reaction due to peanuts (T78.01) T78.01
  8. T78.06
    Anaphylactic reaction due to food additives +7th: A D S
    Needs 7th characterCC AExempt: 2 of 3 7th characters
  9. T78.07
    Anaphylactic reaction due to milk and dairy products
    Header
  10. T78.070
    Anaphylactic reaction due to milk and dairy products with tolerance to baked milk +7th: A D S
    Needs 7th characterCC AExempt: 2 of 3 7th characters
    Excludes1 1

    Excludes1

    • Anaphylactic reaction due to milk and dairy products with reactivity to baked milk (T78.071) T78.071
  11. T78.071
    Anaphylactic reaction due to milk and dairy products with reactivity to baked milk +7th: A D S
    Needs 7th characterCC AExempt: 2 of 3 7th characters
    Excludes1 1

    Excludes1

    • Anaphylactic reaction due to milk and dairy products with tolerance to baked milk (T78.070) T78.070
  12. T78.079
    Anaphylactic reaction due to milk and dairy products, unspecified +7th: A D S
    Needs 7th characterCC AExempt: 2 of 3 7th characters
  13. T78.08
    Anaphylactic reaction due to eggs
    Header
  14. T78.080
    Anaphylactic reaction due to egg with tolerance to baked egg +7th: A D S
    Needs 7th characterCC AExempt: 2 of 3 7th characters
    Excludes1 1

    Excludes1

    • Anaphylactic reaction due to egg with reactivity to baked egg (T78.081) T78.081
  15. T78.081
    Anaphylactic reaction due to egg with reactivity to baked egg +7th: A D S
    Needs 7th characterCC AExempt: 2 of 3 7th characters
    Excludes1 1

    Excludes1

    • Anaphylactic reaction due to egg with tolerance to baked egg (T78.080) T78.080
  16. T78.089
    Anaphylactic reaction due to eggs, unspecified +7th: A D S
    Needs 7th characterCC AExempt: 2 of 3 7th characters
  17. T78.09
    Anaphylactic reaction due to other food products +7th: A D S
    Needs 7th characterCC AExempt: 2 of 3 7th characters
  18. T78.1
    Other adverse food reactions, not elsewhere classified
    Header
    Excludes1 3, Excludes2 6, Use additional code 1

    Excludes1

    • anaphylactic reaction or shock due to adverse food reaction (T78.0-) T78.0
    • anaphylactic reaction due to food (T78.0-) T78.0
    • bacterial food borne intoxications (A05.-) A05

    Excludes2

    • allergic and dietetic gastroenteritis and colitis (K52.29) K52.29
    • allergic rhinitis due to food (J30.5) J30.5
    • dermatitis due to food in contact with skin (L23.6, L24.6, L25.4) L23.6 L24.6 L25.4
    • dermatitis due to ingested food (L27.2) L27.2
    • food protein-induced enterocolitis syndrome (K52.21) K52.21
    • food protein-induced enteropathy (K52.22) K52.22

    Use additional code

    • code to identify the type of reaction, if applicable
  19. T78.11
    Other adverse food reactions due to milk and dairy products
    Header
  20. T78.110
    Other adverse food reactions due to milk and dairy products with tolerance to baked milk +7th: A D S
    Needs 7th characterExempt: 2 of 3 7th characters
    Excludes1 1

    Excludes1

    • Other adverse food reaction due to milk and dairy products with reactivity to baked milk (T78.111) T78.111
  21. T78.111
    Other adverse food reaction due to milk and dairy products with reactivity to baked milk +7th: A D S
    Needs 7th characterExempt: 2 of 3 7th characters
    Excludes1 1

    Excludes1

    • Other adverse food reaction due to milk and dairy products with tolerance to baked milk (T78.110) T78.110
  22. T78.119
    Other adverse food reaction due to milk and dairy products with baked milk tolerance/reactivity, unspecified +7th: A D S
    Needs 7th characterExempt: 2 of 3 7th characters
  23. T78.12
    Other adverse food reaction due to eggs
    Header
  24. T78.120
    Other adverse food reaction due to egg with tolerance to baked egg +7th: A D S
    Needs 7th characterExempt: 2 of 3 7th characters
    Excludes1 1

    Excludes1

    • Other adverse food reaction due to egg with reactivity to baked egg (T78.121) T78.121
  25. T78.121
    Other adverse food reaction due to egg with reactivity to baked egg +7th: A D S
    Needs 7th characterExempt: 2 of 3 7th characters
    Excludes1 1

    Excludes1

    • Other adverse food reaction due to egg with tolerance to baked egg (T78.120) T78.120
  26. T78.129
    Other adverse food reaction due to egg with baked egg tolerance/reactivity, unspecified +7th: A D S
    Needs 7th characterExempt: 2 of 3 7th characters
  27. T78.19
    Other adverse food reactions, not elsewhere classified +7th: A D S
    Needs 7th characterExempt: 2 of 3 7th characters
  28. T78.2
    Anaphylactic shock, unspecified +7th: A D S
    Needs 7th characterCC AExempt: 2 of 3 7th characters
    Inclusion terms 3, Excludes1 3

    Inclusion terms

    • Allergic shock
    • Anaphylactic reaction
    • Anaphylaxis

    Excludes1

    • anaphylactic reaction or shock due to adverse effect of correct medicinal substance properly administered (T88.6) T88.6
    • anaphylactic reaction or shock due to adverse food reaction (T78.0-) T78.0
    • anaphylactic reaction or shock due to serum (T80.5-) T80.5
  29. T78.3
    Angioneurotic edema +7th: A D S
    Needs 7th characterExempt: 2 of 3 7th characters
    Inclusion terms 3, Excludes1 2

    Inclusion terms

    • Allergic angioedema
    • Giant urticaria
    • Quincke's edema

    Excludes1

    • serum urticaria (T80.6-) T80.6
    • urticaria (L50.-) L50
  30. T78.4
    Other and unspecified allergy
    Header
    Excludes1 7

    Excludes1

    • specified types of allergic reaction such as:
    • allergic diarrhea (K52.29) K52.29
    • allergic gastroenteritis and colitis (K52.29) K52.29
    • dermatitis (L23-L25, L27.-) L23 L25 L27
    • food protein-induced enterocolitis syndrome (K52.21) K52.21
    • food protein-induced enteropathy (K52.22) K52.22
    • hay fever (J30.1) J30.1
  31. T78.40
    Allergy, unspecified +7th: A D S
    Needs 7th characterExempt: 2 of 3 7th characters
    Inclusion terms 2

    Inclusion terms

    • Allergic reaction NOS
    • Hypersensitivity NOS
  32. T78.41
    Arthus phenomenon +7th: A D S
    Needs 7th characterExempt: 2 of 3 7th characters
    Inclusion terms 1

    Inclusion terms

    • Arthus reaction
  33. T78.49
    Other allergy +7th: A D S
    Needs 7th characterExempt: 2 of 3 7th characters
  34. T78.8
    Other adverse effects, not elsewhere classified +7th: A D S
    Needs 7th characterExempt: 2 of 3 7th characters

CC/MCC: as a secondary diagnosis, unless the principal diagnosis is on the code’s PDX exclusion list (MS-DRG v44 Appendix C; list on the code card).

Sources of each column. Rows marked +7th need a 7th character: pick one to build the full code; its code card has its own flags.

Instructions

At T78

Excludes2

  • complications of surgical and medical care NEC (T80-T88) T80 T88

Notes that also apply

Block T66-T78 instructions (Code also 6): printed on the block page.

Chapter 19 instructions (Notes 2, Excludes2 2, Use additional code 1): printed on the chapter 19 page.

7th characters

7th characters for T78 defined here

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

7th characters for T78
7thMeaning (NCHS)
Ainitial encounter
Dsubsequent encounter
Ssequela

A code that takes a 7th character is invalid without it; the placeholder X fills a code shorter than 6 characters (Official Guidelines I.A.5). How 7th characters work.

Index entries

  • Angioedema (allergic) (any site) (with urticaria) → T78.3
  • Angioneurotic edema (allergic) (any site) (with urticaria) → T78.3
  • Bannister's disease → T78.3
  • Quincke's disease or edema → T78.3
  • Allergy, allergic (reaction) (to) → T78.40
  • Arthus' phenomenon or reaction → T78.41
  • Allergy, allergic (reaction) (to)dairy products → T78.119
  • Allergy, allergic (reaction) (to)food (any) (ingested) NEC → T78.19
  • Effect, adversefoodstuffs → T78.19
  • Syndromeoral allergy → T78.19
  • Allergy, allergic (reaction) (to)anaphylactic reaction or shock → T78.2
  • Allergy, allergic (reaction) (to)shock (anaphylactic) → T78.2
  • Shockanaphylactic → T78.2
  • Allergy, allergic (reaction) (to)angioneurotic edema → T78.3
  • Disease, diseasedBannister's → T78.3
  • Edema, edematous (infectious) (pitting) (toxic)allergic → T78.3
  • Edema, edematous (infectious) (pitting) (toxic)angioneurotic (allergic) (any site) (with urticaria) → T78.3
  • Edema, edematous (infectious) (pitting) (toxic)circumscribed, acute → T78.3
  • Edema, edematous (infectious) (pitting) (toxic)essential, acute → T78.3
  • Edema, edematous (infectious) (pitting) (toxic)periodic → T78.3
  • Edema, edematous (infectious) (pitting) (toxic)Quincke's → T78.3
  • Gianturticaria → T78.3
  • Urticariawith angioneurotic edema → T78.3
  • Urticariagiant → T78.3
  • Urticariagigantea → T78.3
  • Urticarialarynx → T78.3
  • Allergy, allergic (reaction) (to)drug, medicament & biological (any) (external) (internal) → T78.40
  • Hypersensitive, hypersensitiveness, hypersensitivityreaction → T78.40
  • Allergy, allergic (reaction) (to)specific NEC → T78.49
  • Effect, adversespecified NEC → T78.8
  • Shockanaphylacticdue to food (nonpoisonous) → T78.00
  • Allergy, allergic (reaction) (to)dairy productsanaphylactic reaction → T78.079
  • Allergy, allergic (reaction) (to)milk proteinanaphylactic reaction → T78.079
  • Allergy, allergic (reaction) (to)eggsanaphylactic reaction → T78.089
  • Allergy, allergic (reaction) (to)milk proteinadverse reaction NEC → T78.119
  • Allergy, allergic (reaction) (to)eggsadverse reaction NEC → T78.129
  • Allergy, allergic (reaction) (to)gastrointestinalmeaning other adverse food reaction not elsewhere classified → T78.19
  • Reactionadversefood (any) (ingested) NEC → T78.19
  • Edema, edematous (infectious) (pitting) (toxic)glottis, glottic, glottidis (obstructive) (passive)allergic → T78.3
  • Arthritis, arthritic (acute) (chronic) (nonpyogenic) (subacute)in (due to)hypersensitivity reaction NEC → T78.49 [M36.4]

32 more, longer entries are not listed; the search box finds them by word.

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