2026 ICD-10-CM Diagnosis Code T63.691SToxic effect of contact with other venomous marine animals, accidental (unintentional), sequela
T63.691S is a billable ICD-10-CM diagnosis code for toxic effect of contact with other venomous marine animals, accidental (unintentional), 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 2026 (October 1, 2025 through September 30, 2026) 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 Poisoning/toxic effect/adverse effects/underdosing, sequela.
Code Identity
Code Classification
Present on Admission (POA)Billing
T63.691S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Accidentally stung by nematocyst
- Accidentally stung by sea cucumber
- Autonomic disorder caused by marine toxin
- Bite of venomous animal
- Cutaneous reaction caused by Mollusk venom
- Cutaneous reaction due to octopus bite
- Dermatosis caused by Coelenterata
- Fire coral dermatitis
- Jellyfish sting
- Mollusk sting
- Poisoned bite of blue ring octopus
- Poisoned bite of venomous octopus
- Poisoning by blue ring octopus
- Poisoning by cone shell venom
- Poisoning by marine animal
- Poisoning by sea cucumber
- Poisoning by sea urchin spine
- Poisoning by venomous mollusk
- Poisoning by venomous octopus
- Poisoning due to sting of nematocyst
- Stung by cone shell
- Stung by nematocyst
- Stung by sea cucumber
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Toxic effect of contact with venomous animals and plants (T63). 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 2026, published by CMS and the National Center for Health Statistics.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Table of Drugs and ChemicalsClinical
Substances in the Table of Drugs and Chemicals that reference this code family. Always confirm in the Tabular List before coding.
| Substance | Accidental | Self-harm | Assault | Undetermined | Adverse Effect | Underdosing |
|---|---|---|---|---|---|---|
| Coral (sting) | T63.691 | T63.692 | T63.693 | T63.694 | – | – |
| Coral (sting)::snake (bite) (venom) | T63.691 | T63.692 | T63.693 | T63.694 | – | – |
| Marine (sting) | T63.691 | T63.692 | T63.693 | T63.694 | – | – |
| Marine (sting)::animals (sting) | T63.691 | T63.692 | T63.693 | T63.694 | – | – |
| Marine (sting)::plants (sting) | T63.691 | T63.692 | T63.693 | T63.694 | – | – |
| Nematocyst (sting) | T63.691 | T63.692 | T63.693 | T63.694 | – | – |
Patient EducationClinical
Animal Bites
Wild animals usually avoid people. They might attack, however, if they feel threatened, are sick, or are protecting their young or territory. Attacks by pets are more common. Animal bites rarely are life-threatening, but if they become infected, you can develop serious medical problems.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert T63.691S to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T63.691SOverview
Is T63.691S a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report toxic effect of contact with other venomous marine animals, accidental (unintentional), sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in T63.691S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the toxic effect of contact with other venomous marine animals, accidental (unintentional) itself has resolved, not the original event.
What MS-DRG does T63.691S group to?
When toxic effect of contact with other venomous marine animals, accidental (unintentional), sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.
Is T63.691S 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 toxic effect of contact with other venomous marine animals, accidental (unintentional), sequela on inpatient claims.
What is the ICD-9 equivalent of T63.691S?
Under the General Equivalence Mappings, toxic effect of contact with other venomous marine animals, accidental (unintentional), sequela converts to ICD-9-CM 909.1 (late eff nonmed substanc) and E929.2 (late eff acc poisoning). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
