ICD-10 T59.5X1
Non-Billable HeaderToxic effect of fluorine gas and hydrogen fluoride, accidental (unintentional)
About ICD-10-CM T59.5X1
ICD-10-CM code T59.5X1 represents Toxic effect of fluorine gas and hydrogen fluoride, accidental (unintentional). This is a non-billable header code in the Injury, Poisoning, and External Causes chapter (block T59). The 2026 edition of ICD-10-CM T59.5X1 became effective on October 1, 2025. Non-billable codes cannot be used as a primary or secondary diagnosis on a claim, use a more specific child code instead.
Coding Tips for T59.5X1
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
Injury codes require a 7th character: A (initial encounter, active treatment), D (subsequent, healing/recovery), S (sequela, late effect of original injury). Codes with fewer than 6 characters need the placeholder X to bring them to 6 characters before adding the 7th. Wrong or missing 7th character is the #1 cause of injury claim denials.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under T59.5X1. Per CMS ICD-10-CM Tabular 2026.
- Toxic effect of fluorine gas and hydrogen fluoride NOS
Medicare LCD Coverage for T59.5X1
Local Coverage Determinations (LCDs) from CMS MACs that list T59.5X1 as a covered diagnosis.
This doesn't mean the code isn't covered, it means no MAC has issued a Local Coverage Determination naming this specific code. Coverage may still apply under National Coverage Determinations or general medical-necessity rules.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing T59.5X1.
Our payer policy database covers Aetna, Cigna, Anthem, BCBS, Humana, and Medicare Advantage plans, but T59.5X1 doesn't currently appear in any indexed policy. The code may still be covered under standard plan benefits.
CPT Codes Commonly Billed with T59.5X1
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.
Codes Adjacent To T59.5X1
Other codes in section T51-T65 (Toxic effects of substances chiefly nonmedicinal as to source).
ICD-10 T59.5X1, Billing FAQ
Is ICD-10 code T59.5X1 billable? +
No, T59.5X1 is a non-billable header code. Use a more specific child code from block T59 when submitting claims.
What other names or terms map to T59.5X1? +
ICD-10 T59.5X1 includes: Toxic effect of fluorine gas and hydrogen fluoride NOS.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on May 31, 2026.
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