2026 ICD-10-CM Diagnosis Code S31.109AUnspecified open wound of abdominal wall, unspecified quadrant without penetration into peritoneal cavity, initial encounter
S31.109A is a billable ICD-10-CM diagnosis code for unspecified open wound of abdominal wall, unspecified quadrant without penetration into peritoneal cavity, 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Open wounds of trunk, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Glass in groin
- Glass in trunk
- Injury of appendix with open wound into abdominal cavity
- Injury of kidney with open wound into abdominal cavity
- Injury of rectum with open wound into abdominal cavity
- Injury of tail of pancreas with open wound into abdominal cavity
- Injury to pancreas - open
- Metal foreign body in groin
- Metal foreign body in trunk
- Multiple open wounds of abdomen
- Multiple open wounds of abdomen, lower back and pelvis
- Open avulsion fracture of anterior inferior spine of ilium
- Open avulsion fracture of anterior inferior spine of left ilium
- Open fracture of ilium
- Open fracture of left ilium
- Open fracture of pubis
- Open fracture pelvis, anterior inferior iliac spine
- Open fracture pelvis, iliac wing
- Open injury of kidney
- Open injury of urethra
- Open wound of abdomen
- Open wound of anterior abdominal wall
- Open wound of flank
- Open wound of hypochondrium
- Open wound of hypogastric region
- Open wound of inguinal region
- Open wound of lateral abdominal wall
- Open wound of loin
- Open wounds involving thorax with abdomen, lower back and pelvis
- Retroperitoneum injury with open wound into cavity
- Traumatic amputation of abdomen
- Traumatic injury of tail of pancreas
- Wound of abdomen
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.
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 S31.109A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code History & ChangesHistory
Replaced This code was replaced in the FY 2026 code set by:
- S31.106A - Unsp opn wnd abd wall, right flank w/o penet perit cav, init
- S31.106A - Unsp opn wnd abd wall, right flank w/o penet perit cav, init
- S31.107A - Unsp opn wnd abd wall, left flank w/o penet perit cav, init
- S31.107A - Unsp opn wnd abd wall, left flank w/o penet perit cav, init
- S31.10AA - Unsp opn wnd abd wall, unsp flank w/o penet perit cav, init
- S31.10AA - Unsp opn wnd abd wall, unsp flank w/o penet perit cav, init
Questions About S31.109AOverview
Is S31.109A a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified open wound of abdominal wall, unspecified quadrant without penetration into peritoneal cavity, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S31.109A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for unspecified open wound of abdominal wall, unspecified quadrant without penetration into peritoneal cavity, such as an emergency visit or first evaluation.
What MS-DRG does S31.109A group to?
When unspecified open wound of abdominal wall, unspecified quadrant without penetration into peritoneal cavity, 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 S31.109A?
Under the General Equivalence Mappings, unspecified open wound of abdominal wall, unspecified quadrant without penetration into peritoneal cavity, initial encounter converts to ICD-9-CM 879.4 (opn wnd lateral abdomen). 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.
