2027 ICD-10-CM Diagnosis Code S22.39XKFracture of one rib, unspecified side, subsequent encounter for fracture with nonunion

ICD-10-CM Codes›S00–T88›S20-S29›s

ICD-10-CM S22.39XK
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S22.39XK is a billable ICD-10-CM diagnosis code for fracture of one rib, unspecified side, subsequent encounter for fracture with nonunion. The 7th character K means subsequent encounter for fracture with nonunion. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 564 through 566. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 5,561 closely related codes. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family and exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fracture of torso, subsequent encounter.

Code Identity

ICD-10-CM Code
S22.39XK
Billable Status
Yes — Valid for Submission
Code Describes
Fracture of one rib, unspecified side, subsequent encounter for fracture with nonunion
Short Description
Fracture of one rib, unsp side, subs for fx w nonunion
Parent Code
S22.39
Fracture of one rib, unspecified side

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS20-S29Injuries to the thorax
CategorysFracture of rib, sternum and thoracic spine (S22)
This CodeS22.39XKFracture of one rib, unspecified side, subsequent encounter for fracture with nonunion

Code EditsBilling

Medicare Code Editor checks that affect claim validity for S22.39XK.

Unspecified codes
Unspecified codes exist in the ICD-10-CM classification for circumstances when documentation in the medical record does not provide the level of detail needed to support reporting a more specific code. However, in the inpatient setting, there should generally be very limited and rare circumstances for which the laterality (right, left, bilateral) of a condition is unable to be documented and reported. The following pages contain the list of unspecified ICD-10-CM diagnosis codes for which there is a more specific code to identify laterality (right, left, bilateral) within that code family.

Present on Admission (POA)Billing

S22.39XK is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Injuries to the thorax (S20-S29).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Closed fracture of one rib
  • Closed fracture of rib
  • Fracture of eighth rib
  • Fracture of eleventh rib
  • Fracture of fifth rib
  • Fracture of first rib
  • Fracture of fourth rib
  • Fracture of ninth rib
  • Fracture of one rib
  • Fracture of rib
  • Fracture of second rib
  • Fracture of seventh rib
  • Fracture of sixth rib
  • Fracture of tenth rib
  • Fracture of third rib
  • Fracture of twelfth rib
  • Open fracture of one rib
  • Open fracture of rib

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 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to S22.39XK: its own notes plus those printed at S22, block S20-S29, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From S22 Fracture of rib(s), sternum and thoracic spine applies to 354 codes
  • fracture of thoracic neural arch
  • fracture of thoracic spinous process
  • fracture of thoracic transverse process
  • fracture of thoracic vertebra
  • fracture of thoracic vertebral arch
From Block S20-S29 Injuries to the thorax applies to 1,602 codes
  • injuries of breast
  • injuries of chest (wall)
  • injuries of interscapular area

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From S22 Fracture of rib(s), sternum and thoracic spine applies to 354 codes
  • transection of thorax (S28.1)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From S22 Fracture of rib(s), sternum and thoracic spine applies to 354 codes
From Block S20-S29 Injuries to the thorax applies to 1,602 codes
  • burns and corrosions (T20-T32)
  • effects of foreign body in bronchus (T17.5)
  • effects of foreign body in esophagus (T18.1)
  • effects of foreign body in lung (T17.8)
  • effects of foreign body in trachea (T17.4)
  • frostbite (T33-T34)
  • injuries of axilla
  • injuries of clavicle
  • injuries of scapular region
  • injuries of shoulder
  • insect bite or sting, venomous (T63.4)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Code First

The underlying condition named in the note is sequenced before this code.

From S22 Fracture of rib(s), sternum and thoracic spine applies to 354 codes

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

From S22 Fracture of rib(s), sternum and thoracic spine applies to 354 codes
  • if applicable, any associated condition such as:
  • injury of intrathoracic organ (S27.-)
  • traumatic hemopneumothorax (S27.2)
  • traumatic hemothorax (S27.1-)
  • traumatic pneumothorax (S27.0)

Notes

General instructions on how these codes are used.

From S22 Fracture of rib(s), sternum and thoracic spine applies to 354 codes
  • A fracture not indicated as displaced or nondisplaced should be coded to displaced
  • A fracture not indicated as open or closed should be coded to closed
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

From S22 Fracture of rib(s), sternum and thoracic spine applies to 354 codes
  • The appropriate 7th character is to be added to each code from category S22
Values for category S22 Skull, Spine and Pelvis Fracture Encounter
  • Ainitial encounter for closed fracture
  • Binitial encounter for open fracture
  • Dsubsequent encounter for fracture with routine healing
  • Gsubsequent encounter for fracture with delayed healing
  • Ksubsequent encounter for fracture with nonunion this code
  • Ssequela

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name S22.39XK, its category, or a range that includes it.

Excludes1 3

These codes carry an Excludes1 note naming S22.39XK: they are not reported together with it, unless the two conditions are unrelated.

  • M48.5 Collapsed vertebra, not elsewhere classified
    traumatic fracture of vertebra (S12.-, S22.-, S32.-) names S22.-, which includes this code
  • M84.3 Stress fracture
    traumatic fracture (S12.-, S22.-, S32.-, S42.-, S52.-, S62.-, S72.-, S82.-, S92.-) names S22.-, which includes this code
  • M84.4 Pathological fracture, not elsewhere classified
    traumatic fracture (S12.-, S22.-, S32.-, S42.-, S52.-, S62.-, S72.-, S82.-, S92.-) names S22.-, which includes this code

Code Also 1

These codes say S22.39XK may also be needed to fully describe the condition. The note gives no sequencing direction.

  • S21 Open wound of thorax
    rib fracture (S22.3-, S22.4-) names S22.3-, which includes this code

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ040
Fracture of torso, subsequent encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

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 S22.39XK to ICD-9-CMHistory

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

ICD-9-CM
733.82 Nonunion of fracture
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About S22.39XKOverview

Is S22.39XK (Fracture of one rib, unspecified side) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report fracture of one rib, unspecified side, subsequent encounter for fracture with nonunion on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character K in S22.39XK mean?

The final character K reports a subsequent encounter where the fracture of one rib, unspecified side has failed to heal, called a nonunion. In this category the CMS Tabular List defines K as "subsequent encounter for fracture with nonunion".

What MS-DRG does S22.39XK group to?

When fracture of one rib, unspecified side, subsequent encounter for fracture with nonunion is the principal diagnosis on an inpatient stay, it groups to MS-DRG 564, 566, 565, with relative weights from 0.7374 to 1.4909 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S22.39XK a CC or MCC?

CMS lists S22.39XK as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 5,561 closely related codes in its exclusion list.

Is S22.39XK 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 one rib, unspecified side, subsequent encounter for fracture with nonunion on inpatient claims. The code appears in the Injuries to the thorax (S20-S29) range of the CMS exempt list.