Is T66.XXXD a billable ICD-10 code?

Yes. T66.XXXD (Radiation sickness, unspecified, subsequent encounter) is billable and can be used for insurance claims. Always verify payer-specific requirements.

T66.XXXD ✓ Billable

Radiation sickness, unspecified, subsequent encounter

Q: What is ICD-10 code T66.XXXD?

ICD-10-CM code T66.XXXD stands for "Radiation sickness, unspecified, subsequent encounter". It is a billable code in the Injury, Poisoning and Certain Other Consequences of External Causes chapter, effective FY2026 (Oct 1, 2025 – Sep 30, 2026).

ICD-10-CM · FY2026 · Injury, Poisoning and Certain Other Consequences of External Causes

Code

T66.XXXD

System

ICD-10-CM

Billable

Yes — valid for submission

Effective

FY2026

Chapter

Injury, Poisoning and Certain Other Consequences of External Causes

Source

CMS / CDC NCHS

⚠ Verify before billing. Confirm against the current CMS/NCHS ICD-10-CM files and your payer's rules before claims submission.

Frequently asked questions

What is ICD-10 code T66.XXXD?

ICD-10-CM code T66.XXXD represents Radiation sickness, unspecified, subsequent encounter. It is a billable diagnosis code in the Injury, Poisoning and Certain Other Consequences of External Causes chapter, effective October 1, 2025 – September 30, 2026.

Is T66.XXXD billable?

Yes. T66.XXXD is a valid billable ICD-10-CM code for insurance claims and clinical documentation.

What chapter is T66.XXXD in?

T66.XXXD belongs to the Injury, Poisoning and Certain Other Consequences of External Causes chapter (S00–T88) of ICD-10-CM.

Related codes in the T66 category

T66 Radiation sickness, unspecified Non-billable T66.XXXA Radiation sickness, unspecified, initial encounter Billable T66.XXXS Radiation sickness, unspecified, sequela Billable

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