Is ICD-10-CM code T21 billable?

No, T21 (Burn and corrosion of trunk) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code T21 belong to?

T21 belongs to Chapter 19 of the ICD-10-CM tabular list: S00–T88 (Injury, Poisoning and Certain Other Consequences of External Causes).

T21Not billable, use a more specific code below

Burn and corrosion of trunk

In Burns and corrosions of external body surface, specified by site (T20-T25), chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes

216 billable codes under T21: 18 are a CC; none map to an HCC.A CC or MCC (major CC) is a secondary diagnosis that raises the MS-DRG payment.

Instructional notes

Includes: conditions that are coded here

burns and corrosion of hip region

Excludes2: not included here, code separately if applicable

burns and corrosion of axilla (T22.- with fifth character 4)
burns and corrosion of scapular region (T22.- with fifth character 6)
burns and corrosion of shoulder (T22.- with fifth character 5)

Also applies, from Burns and corrosions of external body surface, specified by site (T20-T25)

These notes sit on T20-T25 and apply to every code under it, including T21.

Includes: conditions that are coded here

burns and corrosions of first degree [erythema]
burns and corrosions of second degree [blisters][epidermal loss]
burns and corrosions of third degree [deep necrosis of underlying tissue] [full- thickness skin loss]

Use additional code: add a second code for this, listed after this one

code from category T31 or T32 to identify extent of body surface involved

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Section I.C.19.d Coding of Burns and Corrosions (page 80), covers T21
Sequence the highest degree burn first and code each site separately, using the highest degree for one site. Code non-healing burns as acute, add codes for infection, and add an external cause code for source, intent, and place.

All codes under T21

T21 can't be used on a claim. Pick a billable code below; grey headings group them.

T21 MS-DRGs

As the principal diagnosis, the billable codes under T21 group to MS-DRG 604, 605, 949, 950, or 935 (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

DRG 604 Trauma to the Skin, Subcutaneous Tissue and Breast with MCC (72 of 216 codes)
DRG 605 Trauma to the Skin, Subcutaneous Tissue and Breast without MCC (72 of 216 codes)
DRG 949 Aftercare with CC/MCC (72 of 216 codes)
DRG 950 Aftercare without CC/MCC (72 of 216 codes)
DRG 935 Non-Extensive Burns (54 of 216 codes)

Other codes that refer to T21

Notes on these codes point to T21.

T22 Excludes2: burn and corrosion of interscapular region (T21.-)
T24 Excludes2: burn and corrosion of hip region (T21.-)

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

Burns

A burn is damage to your body's tissues caused by heat, chemicals, electricity, sunlight, or radiation. Scalds from hot liquids and steam, building fires and flammable liquids and gases are the most common causes of burns. Another kind is an inhalation injury, caused by breathing smoke.

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.