2026 ICD-10-CM Diagnosis Code S21.021SLaceration with foreign body of right breast, sequela
S21.021S is a billable ICD-10-CM diagnosis code for laceration with foreign body of right breast, 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 604 through 605. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury, sequela.
Code Identity
Code Classification
Present on Admission (POA)Billing
S21.021S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Open wound of thorax (S21). 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
Foreign Bodies
If you've ever gotten a splinter or had sand in your eye, you've had experience with a foreign body. A foreign body is something that is stuck inside you but isn't supposed to be there. You may inhale or swallow a foreign body, or you may get one from an injury to almost any part of your body.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S21.021S to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S21.021SOverview
Is S21.021S (Laceration with foreign body of right breast) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report laceration with foreign body of right breast, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in S21.021S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the laceration with foreign body of right breast itself has resolved, not the original event.
What MS-DRG does S21.021S group to?
When laceration with foreign body of right breast, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 604, 605, with relative weights from 0.9160 to 1.4721 depending on complications. Higher weights mean higher Medicare reimbursement.
Is S21.021S 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 laceration with foreign body of right breast, sequela on inpatient claims.
What is the ICD-9 equivalent of S21.021S?
Under the General Equivalence Mappings, laceration with foreign body of right breast, sequela converts to ICD-9-CM 906.0 (lt eff opn wnd head/trnk). 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.
