2026 ICD-10-CM Diagnosis Code S82.853BDisplaced trimalleolar fracture of unspecified lower leg, initial encounter for open fracture type I or II
S82.853B is a billable ICD-10-CM diagnosis code for displaced trimalleolar fracture of unspecified lower leg, initial encounter for open fracture type I or II. The 7th character B reports the initial encounter for an open fracture. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 562 through 563, 963 through 965. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fracture of the lower limb (except hip), initial encounter.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for S82.853B.
Quality Payment Program MeasuresBilling
Medicare quality measures that can apply when S82.853B is part of the patient record.
Communication with the Physician or Other Clinician Managing On-Going Care Post-Fracture for Men and Women Aged 50 Years and Older
High Priority: YES
Measure Type: Process
Submission Methods: Claims, Registry
Description: Percentage of patients aged 50 years and older treated for a fracture with documentation of communication, between the physician treating the fracture and the physician or other clinician managing the patient's on-going care, that a fracture occurred and that the patient was or should be considered for osteoporosis treatment or testing. This measure is submitted by the physician who treats the fracture and who therefore is held accountable for the communication.
Osteoporosis Management in Women Who Had a Fracture
High Priority: NO
Measure Type: Process
Submission Methods: Claims, Registry
Description: The percentage of women 50-85 years of age who suffered a fracture and who had either a bone mineral density (BMD) test or prescription for a drug to treat osteoporosis in the six months after the fracture.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Closed bimalleolar fracture
- Closed fracture ankle, trimalleolar, high fibular fracture
- Closed fracture ankle, trimalleolar, low fibular fracture
- Closed fracture of distal tibia and distal fibula
- Closed trimalleolar fracture
- Open bimalleolar fracture
- Open fracture ankle, trimalleolar, high fibular fracture
- Open fracture ankle, trimalleolar, low fibular fracture
- Open fracture of distal tibia and distal fibula
- Open fracture of medial malleolus
- Open fracture of tibia AND fibula
- Open trimalleolar fracture
- Trimalleolar fracture
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
Ankle Injuries and Disorders
Your ankle bone and the ends of your two lower leg bones make up the ankle joint. Your ligaments, which connect bones to one another, stabilize and support it. Your muscles and tendons move it.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S82.853B to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S82.853BOverview
Is S82.853B (Displaced trimalleolar fracture of unspecified lower leg) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report displaced trimalleolar fracture of unspecified lower leg, initial encounter for open fracture type I or II on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character B in S82.853B mean?
The final character B reports the initial encounter for an open fracture, in this case involving the displaced trimalleolar fracture of unspecified lower leg.
What MS-DRG does S82.853B group to?
When displaced trimalleolar fracture of unspecified lower leg, initial encounter for open fracture type I or II is the principal diagnosis on an inpatient stay, it groups to MS-DRG 562, 563, 963, 964, 965, with relative weights from 0.8955 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of S82.853B?
Under the General Equivalence Mappings, displaced trimalleolar fracture of unspecified lower leg, initial encounter for open fracture type I or II converts to ICD-9-CM 824.7 (fx trimalleolar-open). 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.
