Alphabetic Index FY2027

T61.784

Other shellfish poisoning, undetermined

FY2027Chapter 19: Injury, poisoning and certain other consequences of external causes/T51–T65 Toxic effects of substances chiefly nonmedicinal as to source

Non-billable headerNot valid on its own. Use one of the more specific codes under it.

T61.784 is a non-billable ICD-10-CM code header for other shellfish poisoning, undetermined. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. A 7th character is required to complete the code. Its coding notes include a Use additional code instruction, 14 Excludes1 entries and 2 Excludes2 entries.

7th character

Category T61 requires a 7th character.

Assembled code T61.784A Open code

Guidelines tips

From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.

The 7th character depends on whether the patient is in active treatment, not on who sees the patient. An aftercare Z code is not used for injury aftercare.

Guidelines I.C.19.aInjuries: application of 7th charactersRead the official text

T36-T65 codes already include the substance and the intent, so no additional external cause code is required. Do not code directly from the Table of Drugs and Chemicals.

Guidelines I.C.19.ePoisoning, adverse effects and the Table of DrugsRead the official text

Use additional code

Add the listed code as a secondary code, if known.

Also from chapter/block level (5 notes)
Inherited from T51–T65 Toxic effects of substances chiefly nonmedicinal as to source
  • code(s):
    • for all associated manifestations of toxic effect, such as: respiratory conditions due to external agents (J60-J70)
    • personal history of foreign body fully removed (Z87.821)
    • to identify any retained foreign body, if applicable (Z18.-)
Inherited from Chapter 19 Injury, poisoning and certain other consequences of external causes
  • code to identify any retained foreign body, if applicable (Z18.-)

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Inherited from T61 Toxic effect of noxious substances eaten as seafood
  • allergic reaction to food, such as:
    • anaphylactic reaction or shock due to adverse food reaction (T78.0-)
    • bacterial foodborne intoxications (A05.-)
    • dermatitis (L23.6, L25.4, L27.2)
    • food protein-induced enterocolitis syndrome (K52.21)
    • food protein-induced enteropathy (K52.22)
    • gastroenteritis (noninfective) (K52.29)
    • toxic effect of aflatoxin and other mycotoxins (T64)
    • toxic effect of cyanides (T65.0-)
    • toxic effect of harmful algae bloom (T65.82-)
    • toxic effect of hydrogen cyanide (T57.3-)
    • toxic effect of mercury (T56.1-)
    • toxic effect of red tide (T65.82-)
Also from chapter/block level (1 note)
Inherited from T51–T65 Toxic effects of substances chiefly nonmedicinal as to source
  • contact with and (suspected) exposure to toxic substances (Z77.-)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Also from chapter/block level (2 notes)
Inherited from Chapter 19 Injury, poisoning and certain other consequences of external causes
  • birth trauma (P10-P15)
  • obstetric trauma (O70-O71)

Notes

Also from chapter/block level (3 notes)
Inherited from T51–T65 Toxic effects of substances chiefly nonmedicinal as to source
  • When no intent is indicated code to accidental. Undetermined intent is only for use when there is specific documentation in the record that the intent of the toxic effect cannot be determined.
Inherited from Chapter 19 Injury, poisoning and certain other consequences of external causes
  • 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 codes under T61.784 3