2027 ICD-10-CM Diagnosis Code S89.302KUnspecified physeal fracture of lower end of left fibula, subsequent encounter for fracture with nonunion

ICD-10-CM Codes›S00–T88›S80-S89›S89

ICD-10-CM S89.302K
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S89.302K is a billable ICD-10-CM diagnosis code for unspecified physeal fracture of lower end of left fibula, 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 exempt from POA reporting. Coders also document this condition as closed fracture of distal left fibula. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fracture of lower limb (except hip), subsequent encounter.

Code Identity

ICD-10-CM Code
S89.302K
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified physeal fracture of lower end of left fibula, subsequent encounter for fracture with nonunion
Short Description
Unsp physl fx lower end of l fibula, subs for fx w nonunion
Parent Code
S89.302
Unspecified physeal fracture of lower end of left fibula

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS80-S89Injuries to the knee and lower leg
CategoryS89Other and unspecified injuries of lower leg
This CodeS89.302KUnspecified physeal fracture of lower end of left fibula, subsequent encounter for fracture with nonunion

Present on Admission (POA)Billing

S89.302K is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Injuries to the knee and lower leg (S80-S89).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Closed fracture of distal left fibula
  • Closed fracture of epiphyseal plate of distal fibula
  • Closed fracture of epiphyseal plate of distal left fibula
  • Closed fracture of left ankle
  • Closed fracture of left fibula

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 S89.302K: its own notes plus those printed at S89, block S80-S89, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

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 S89 Other and unspecified injuries of lower leg applies to 378 codes
  • other and unspecified injuries of ankle and foot (S99.-)
From Block S80-S89 Injuries to the knee and lower leg applies to 4,680 codes
  • burns and corrosions (T20-T32)
  • frostbite (T33-T34)
  • injuries of ankle and foot, except fracture of ankle and malleolus (S90-S99)
  • 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

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.-)

Notes

General instructions on how these codes are used.

From S89 Other and unspecified injuries of lower leg applies to 378 codes
  • 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 S89 Other and unspecified injuries of lower leg applies to 378 codes
  • The appropriate 7th character is to be added to each code from subcategories S89.0, S89.1, S89.2, and S89.3
Values for category S89 Closed Fracture Encounter
  • Ainitial encounter for closed fracture
  • Dsubsequent encounter for fracture with routine healing
  • Gsubsequent encounter for fracture with delayed healing
  • Ksubsequent encounter for fracture with nonunion this code
  • Psubsequent encounter for fracture with malunion
  • Ssequela

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

Clinical ClassificationClinical

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

CCSR INJ042
Fracture of lower limb (except hip), subsequent encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Fractures

A fracture is a break in a bone. Fractures are usually caused by injuries. Since they can sometimes be serious, it's important to get medical care right away if you think you have a fracture.

The full article covers:

  • What is a fracture?
  • What are the different types of fractures?
  • What causes fractures?
  • What are the symptoms of a fracture?
  • How are fractures diagnosed?
  • What are the treatments for fractures?
  • Can fractures be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert S89.302K 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 S89.302KOverview

Is S89.302K (Unspecified physeal fracture of lower end of left fibula) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified physeal fracture of lower end of left fibula, 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 S89.302K mean?

The final character K reports a subsequent encounter where the unspecified physeal fracture of lower end of left fibula 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 S89.302K group to?

When unspecified physeal fracture of lower end of left fibula, 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 S89.302K a CC or MCC?

CMS lists S89.302K 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 S89.302K 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 unspecified physeal fracture of lower end of left fibula, subsequent encounter for fracture with nonunion on inpatient claims. The code appears in the Injuries to the knee and lower leg (S80-S89) range of the CMS exempt list.