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ICD-10-CM 2027 diagnosis code

S31.021ALaceration with foreign body of lower back and pelvis with penetration into retroperitoneum, initial encounter

✓ Billable / specificRequires 7th characterMCC — major complication/comorbidity

S31.021A is a valid, billable ICD-10-CM code for laceration with foreign body of lower back and pelvis with penetration into retroperitoneum, initial encounter. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Lac w fb of lower back and pelvis w penet retroperiton, init

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About S31.021A

S31.021A is the ICD-10-CM diagnosis code for laceration with foreign body of lower back and pelvis with penetration into retroperitoneum, initial encounter. It belongs to category S31 (open wound of abdomen, lower back, pelvis and external genitals), block S30-S39 (injuries to the abdomen, lower back, lumbar spine, pelvis and external genitals) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

The 7th character "A" means initial encounter: use it while the patient is receiving active treatment for the condition.

As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 698 (Other Kidney and Urinary Tract Diagnoses with MCC, relative weight 1.6398), DRG 699 (Other Kidney and Urinary Tract Diagnoses with CC, relative weight 1.0003), DRG 700 (Other Kidney and Urinary Tract Diagnoses without CC/MCC, relative weight 0.6741), DRG 963 (Other Multiple Significant Trauma with MCC, relative weight 2.6363), DRG 964 (Other Multiple Significant Trauma with CC, relative weight 1.4972) and DRG 965 (Other Multiple Significant Trauma without CC/MCC, relative weight 1.0059), in MDC 11 (Diseases and Disorders of the Kidney and Urinary Tract) and MDC 24 (Multiple Significant Trauma), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 868.14 (injury to other intra-abdominal organs with open wound into cavity, retroperitoneum).

7th character

Ainitial encounter

CC/MCC status for this injury by encounter: MCC for A; Neither CC nor MCC for D, S.

Other encounter types for S31.021:

Notes that apply from higher levels

Instructions written at a parent level also apply to S31.021A.

› From S31 Open wound of abdomen, lower back, pelvis and external genitals
Excludes1
  • traumatic amputation of part of abdomen, lower back and pelvis (S38.2-, S38.3)
Excludes2
Code also

Broader instructions also apply from S30-S39 Injuries to the abdomen, lower back, lumbar spine, pelvis and external genitals and Chapter 19: Injury, poisoning and certain other consequences of external causes.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • 868.14Injury to other intra-abdominal organs with open wound into cavity, retroperitoneumapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about S31.021A

Is S31.021A billable?

Yes. S31.021A is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

What does the "A" at the end of S31.021A mean?

It is the 7th character for initial encounter. Per the official guidelines, use it while the patient is receiving active treatment for the condition.

Can S31.021A be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict S31.021A as a principal diagnosis.

Is S31.021A a CC or MCC?

S31.021A is an MCC (major complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.

What DRG does S31.021A group to?

S31.021A is used in the MS-DRG v44.0 logic for MS-DRG 698 (Other Kidney and Urinary Tract Diagnoses with MCC), MS-DRG 699 (Other Kidney and Urinary Tract Diagnoses with CC), MS-DRG 700 (Other Kidney and Urinary Tract Diagnoses without CC/MCC), MS-DRG 963 (Other Multiple Significant Trauma with MCC), MS-DRG 964 (Other Multiple Significant Trauma with CC) and MS-DRG 965 (Other Multiple Significant Trauma without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for S31.021A?

The CMS General Equivalence Mappings map S31.021A to ICD-9-CM 868.14.