2026 ICD-10-CM Diagnosis Code S31.010ALaceration without foreign body of lower back and pelvis without penetration into retroperitoneum, initial encounter

ICD-10-CM CodesS00–T88S30-S39S31

ICD-10-CM S31.010A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S31.010A is a billable ICD-10-CM diagnosis code for laceration without foreign body of lower back and pelvis without penetration into retroperitoneum, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 604 through 605, 963 through 965. Coders also document this condition as cut of back. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Open wounds of trunk, initial encounter.

Code Identity

ICD-10-CM Code
S31.010A
Billable Status
Yes — Valid for Submission
Code Describes
Laceration without foreign body of lower back and pelvis without penetration into retroperitoneum, initial encounter
Short Description
Lac w/o fb of low back and pelv w/o penet retroperiton, init
Parent Code
Laceration without foreign body of lower back and pelvis without penetration into retroperitoneum

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS30-S39Injuries to the abdomen, lower back, lumbar spine, pelvis and external genitals
CategoryS31Open wound of abdomen, lower back, pelvis and external genitals
This CodeS31.010ALaceration without foreign body of lower back and pelvis without penetration into retroperitoneum, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Cut of back
  • Cut of pelvic region
  • Cut of skin of lower back
  • Laceration of lower back
  • Laceration of lower back without foreign body
  • Laceration of pelvic region
  • Laceration of pelvis without foreign body
  • Stab wound of pelvic region

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Open wound of abdomen, lower back, pelvis and external genitals (S31). 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 INJ013
Open wounds of trunk, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Wounds and Injuries

An injury is damage to your body. It is a general term that refers to harm caused by accidents, falls, hits, weapons, and more. In the U.S., millions of people injure themselves every year. These injuries range from minor to life-threatening.

Read the full article at MedlinePlus

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

Convert S31.010A to ICD-9-CMHistory

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

ICD-9-CM
876.0 Open wound of back
Approximate The match is approximate rather than exact.
ICD-9-CM
879.6 Open wound of trunk NEC
Approximate The match is approximate rather than exact.
ICD-9-CM
879.8 Open wound site NOS
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 S31.010AOverview

Is S31.010A a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report laceration without foreign body of lower back and pelvis without penetration into retroperitoneum, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S31.010A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for laceration without foreign body of lower back and pelvis without penetration into retroperitoneum, such as an emergency visit or first evaluation.

What MS-DRG does S31.010A group to?

When laceration without foreign body of lower back and pelvis without penetration into retroperitoneum, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 604, 605, 963, 964, 965, with relative weights from 0.9160 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S31.010A?

Under the General Equivalence Mappings, laceration without foreign body of lower back and pelvis without penetration into retroperitoneum, initial encounter converts to ICD-9-CM 876.0 (open wound of back), 879.6 (open wound of trunk NEC), and 879.8 (open wound site NOS). 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.