2026 ICD-10-CM Diagnosis Code T70.3XXSCaisson disease [decompression sickness], sequela

ICD-10-CM Codes›S00–T88›T66-T78›T70

ICD-10-CM T70.3XXS
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T70.3XXS is a billable ICD-10-CM diagnosis code for caisson disease [decompression sickness], 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 Effect of other external causes, sequela.

Code Identity

ICD-10-CM Code
T70.3XXS
Billable Status
Yes — Valid for Submission
Code Describes
Caisson disease [decompression sickness], sequela
Short Description
Caisson disease [decompression sickness], sequela
Same as the full description in the CMS dataset.
Parent Code
T70.3
Caisson disease [decompression sickness]

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT66-T78Other and unspecified effects of external causes
CategoryT70Effects of air pressure and water pressure
This CodeT70.3XXSCaisson disease [decompression sickness], sequela

Present on Admission (POA)Billing

T70.3XXS 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.

  • Bends
  • Brown-Séquard syndrome due to decompression sickness
  • Cardiovascular decompression injury
  • Cerebellar decompression injury
  • Cerebral decompression injury
  • Cutaneous bends
  • Decompression sickness type I
  • Decompression sickness type II
  • Diving barotrauma
  • Musculoskeletal decompression sickness
  • Neurological decompression syndrome
  • Osteonecrosis due to Caisson disease
  • Pulmonary barotrauma
  • Pulmonary decompression injury
  • Spinal cord decompression injury
  • Visceral decompression injury

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Effects of air pressure and water pressure (T70). 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.

CCSR INJ074
Effect of other external causes, sequela
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Barotrauma

Barotrauma means injury to your body because of changes in barometric (air) or water pressure. One common type happens to your ear. A change in altitude may cause your ears to hurt. This can happen if you are flying in an airplane, driving in the mountains, or scuba diving.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert T70.3XXS to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
909.4 Late eff cert ext cause
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About T70.3XXSOverview

Is T70.3XXS (Caisson disease [decompression sickness]) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report caisson disease [decompression sickness], sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in T70.3XXS mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the caisson disease [decompression sickness] itself has resolved, not the original event.

What MS-DRG does T70.3XXS group to?

When caisson disease [decompression sickness], 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 T70.3XXS 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 caisson disease [decompression sickness], sequela on inpatient claims.

What is the ICD-9 equivalent of T70.3XXS?

Under the General Equivalence Mappings, caisson disease [decompression sickness], sequela converts to ICD-9-CM 909.4 (late eff cert ext cause). 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.