2026 ICD-10-CM Diagnosis Code S99.201BUnspecified physeal fracture of phalanx of right toe, initial encounter for open fracture
S99.201B is a billable ICD-10-CM diagnosis code for unspecified physeal fracture of phalanx of right toe, initial encounter for open fracture. 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 913 through 914, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fracture of the lower limb (except hip), initial encounter.
Code Identity
Code Classification
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
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 S99.201B to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code History & ChangesHistory
Replacement S99.201B replaces the following previously assigned code(s):
- S92.009B - Unsp fracture of unsp calcaneus, init for opn fx
Questions About S99.201BOverview
Is S99.201B (Unspecified physeal fracture of phalanx of right toe) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified physeal fracture of phalanx of right toe, initial encounter for open fracture on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character B in S99.201B mean?
The final character B reports the initial encounter for an open fracture, in this case involving the unspecified physeal fracture of phalanx of right toe.
What MS-DRG does S99.201B group to?
When unspecified physeal fracture of phalanx of right toe, initial encounter for open fracture is the principal diagnosis on an inpatient stay, it groups to MS-DRG 913, 914, 963, 964, 965, with relative weights from 0.8855 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of S99.201B?
Under the General Equivalence Mappings, unspecified physeal fracture of phalanx of right toe, initial encounter for open fracture converts to ICD-9-CM 826.1 (fx phalanx, foot-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.
