T31.86
Burns involving 80-89% of body surface with 60-69% third degree burns
T31.86 (also written T3186) is a billable ICD-10-CM diagnosis code for burns involving 80-89% of body surface with 60-69% third degree burns. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 55 codes in category T31 (Burns classified according to extent of body surface involved). The Alphabetic Index lists it under 2 entries. Its coding notes include a Use additional code instruction and 2 Excludes2 entries.
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.
T31 and T32 are used for acute burns when the site is not specified or additional data is needed, and not for sequelae.
Use additional code
Add the listed code as a secondary code, if known.
Also from chapter/block level (1 note)
- code to identify any retained foreign body, if applicable (Z18.-)
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (2 notes)
- birth trauma (P10-P15)
- obstetric trauma (O70-O71)
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
IRF 60% Rule
On the CMS list of diagnoses used to determine presumptive compliance with the IRF 60 percent rule.
Source: CMS IRF Presumptive Compliance-3, FY 2027 IRF PPS final rule files, effective for discharges on or after October 1, 2026Hospital MCC
Counts as a major complication or comorbidity (MCC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 110 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.
Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix CHAC
On the CMS list of hospital-acquired conditions (HAC 05: Falls and Trauma). When the claim reports it with a present-on-admission (POA) indicator of N (not present) or U (documentation insufficient), CMS does not pay the CC or MCC DRG for it. A POA of Y (present) or W (clinically undetermined) is paid normally.
Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix I; CMS Hospital-Acquired Conditions (HAC) Coding page, POA indicator payment tableNotes
- This category is to be used as the primary code only when the site of the burn is unspecified. It should be used as a supplementary code with categories T20-T25 when the site is specified.
Also from chapter/block level (2 notes)
- 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.
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 2 entries
- Burn (electricity) (flame) (hot gas, liquid or hot object) (radiation) (steam) (thermal), extent (percentage of body surface), 80-89 percent, with 60-69 percent third degree burns
- Burn (electricity) (flame) (hot gas, liquid or hot object) (radiation) (steam) (thermal), unspecified site with extent of body surface involved specified, 80-89 percent (0-9 percent third degree), with, 60-69 percent third degree