2026 ICD-10-CM Diagnosis Code S22.21XKFracture of manubrium, subsequent encounter for fracture with nonunion
S22.21XK is a billable ICD-10-CM diagnosis code for fracture of manubrium, subsequent encounter for fracture with nonunion. The 7th character K reports a subsequent encounter for a fracture that has failed to heal, called a nonunion. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 564 through 566. The code is exempt from POA reporting. Coders also document this condition as fracture of manubrium sterni. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fracture of torso, subsequent encounter.
Code Identity
Code Classification
Present on Admission (POA)Billing
S22.21XK 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.
- Fracture of manubrium sterni
Coding GuidelinesGuidance
The principles of multiple coding of injuries should be followed in coding fractures. Fractures of specified sites are coded individually by site, to the level of detail furnished by medical record content.
A fracture not indicated as open or closed should be coded to closed. A fracture not indicated whether displaced or not displaced should be coded to displaced.
Initial vs. Subsequent Encounter for Fractures
Traumatic fractures are coded using the appropriate 7th character for initial encounter (A, B, C) while the patient is receiving active treatment for the fracture. The appropriate 7th character for initial encounter should also be assigned for a patient who delayed seeking treatment for the fracture or nonunion.
Fractures are coded using the appropriate 7th character for subsequent care for encounters after the patient has completed active treatment of the fracture and is receiving routine care for the fracture during the healing or recovery phase.
Care for complications of surgical treatment for fracture repairs during the healing or recovery phase should be coded with the appropriate complication codes.
Care of complications of fractures, such as malunion and nonunion, should be reported with the appropriate 7th character for subsequent care with nonunion (K, M, N) or subsequent care with malunion (P, Q, R).
The open fracture designations in the assignment of the 7th character for fractures of the forearm, femur and lower leg, including ankle are based on the Gustilo open fracture classification. When the Gustilo classification type is not specified for an open fracture, the 7th character for open fracture type I or II should be assigned (B, E, H, M, Q).
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
Chest Injuries and Disorders
The chest is the part of your body between your neck and your abdomen (belly). The medical term for your chest is thorax.
The full article covers:
- What is the chest?
- What are chest injuries and disorders?
- How are chest injuries and disorders diagnosed?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S22.21XK to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S22.21XKOverview
Is S22.21XK (Fracture of manubrium) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report fracture of manubrium, subsequent encounter for fracture with nonunion on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character K in S22.21XK mean?
The final character K reports a subsequent encounter where the fracture of manubrium has failed to heal, called a nonunion.
What MS-DRG does S22.21XK group to?
When fracture of manubrium, subsequent encounter for fracture with nonunion is the principal diagnosis on an inpatient stay, it groups to MS-DRG 564, 565, 566, with relative weights from 0.7493 to 1.5436 depending on complications. Higher weights mean higher Medicare reimbursement.
Is S22.21XK 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 fracture of manubrium, subsequent encounter for fracture with nonunion on inpatient claims.
What is the ICD-9 equivalent of S22.21XK?
Under the General Equivalence Mappings, fracture of manubrium, subsequent encounter for fracture with nonunion converts to ICD-9-CM 733.82 (nonunion of fracture). 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.
