2026 ICD-10-CM Diagnosis Code S52.91XPUnspecified fracture of right forearm, subsequent encounter for closed fracture with malunion

ICD-10-CM CodesS00–T88S50-S59S52

ICD-10-CM S52.91XP
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S52.91XP is a billable ICD-10-CM diagnosis code for unspecified fracture of right forearm, subsequent encounter for closed fracture with malunion. The 7th character P reports a subsequent encounter for a fracture that has healed in a faulty position, called a malunion. 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 closed fracture of right forearm. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fracture of the upper limb, subsequent encounter.

Code Identity

ICD-10-CM Code
S52.91XP
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified fracture of right forearm, subsequent encounter for closed fracture with malunion
Short Description
Unsp fracture of right forearm, subs for clos fx w malunion
Parent Code
Unspecified fracture of right forearm

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS50-S59Injuries to the elbow and forearm
CategoryS52Fracture of forearm
This CodeS52.91XPUnspecified fracture of right forearm, subsequent encounter for closed fracture with malunion

Present on Admission (POA)Billing

S52.91XP 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.

  • Closed fracture of right forearm
  • Closed fracture of right radius
  • Fracture of bone of right forearm
  • Fracture of right radius
  • Open fracture of right forearm
  • Open fracture of right radius

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.

CCSR INJ041
Fracture of the upper limb, subsequent encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Arm Injuries and Disorders

Of the 206 bones in your body, three of them are in your arm: the humerus, radius, and ulna. Your arms are also made up of muscles, joints, tendons, and other connective tissue. Injuries to any of these parts of the arm can occur during sports, a fall, or an accident.

Read the full article at MedlinePlus

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

Convert S52.91XP to ICD-9-CMHistory

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

ICD-9-CM
733.81 Malunion 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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About S52.91XPOverview

Is S52.91XP (Unspecified fracture of right forearm) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified fracture of right forearm, subsequent encounter for closed fracture with malunion on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character P in S52.91XP mean?

The final character P reports a subsequent encounter where the unspecified fracture of right forearm has healed in a faulty position, called a malunion.

What MS-DRG does S52.91XP group to?

When unspecified fracture of right forearm, subsequent encounter for closed fracture with malunion 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 S52.91XP 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 fracture of right forearm, subsequent encounter for closed fracture with malunion on inpatient claims.

What is the ICD-9 equivalent of S52.91XP?

Under the General Equivalence Mappings, unspecified fracture of right forearm, subsequent encounter for closed fracture with malunion converts to ICD-9-CM 733.81 (malunion 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.