2026 ICD-10-CM Diagnosis Code S83.521DSprain of posterior cruciate ligament of right knee, subsequent encounter

ICD-10-CM Codes›S00–T88›S80-S89›S83

ICD-10-CM S83.521D
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S83.521D is a billable ICD-10-CM diagnosis code for sprain of posterior cruciate ligament of right knee, subsequent encounter. The 7th character D marks it as a subsequent encounter code, used during routine care in the healing or recovery phase. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 949 through 950. The code is exempt from POA reporting. Coders also document this condition as deficiency of posterior cruciate ligament. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sprains and strains, subsequent encounter.

This medical diagnosis code is frequently used in Orthopedics medical specialties to designate conditions such selected sprains rotator cuff, cruciate ligament, and ankle.

Code Identity

ICD-10-CM Code
S83.521D
Billable Status
Yes — Valid for Submission
Code Describes
Sprain of posterior cruciate ligament of right knee, subsequent encounter
Short Description
Sprain of posterior cruciate ligament of right knee, subs
Parent Code
S83.521
Sprain of posterior cruciate ligament of right knee

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS80-S89Injuries to the knee and lower leg
CategoryS83Dislocation and sprain of joints and ligaments of knee
This CodeS83.521DSprain of posterior cruciate ligament of right knee, subsequent encounter

Present on Admission (POA)Billing

S83.521D 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.

  • Deficiency of posterior cruciate ligament
  • Right knee joint posterior cruciate ligament traumatic rupture
  • Rupture of posterior cruciate ligament
  • Sprain of cruciate ligament of knee
  • Sprain of cruciate ligament of right knee joint
  • Sprain of posterior cruciate ligament of knee
  • Sprain of posterior cruciate ligament of right knee joint
  • Sprain of right knee
  • Traumatic tear of cruciate ligament of knee
  • Traumatic tear of cruciate ligament of right knee

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Dislocation and sprain of joints and ligaments of knee (S83). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

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 INJ061
Sprains and strains, subsequent encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Knee Injuries and Disorders

Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt or diseased, you have knee problems. Knee problems can cause pain and difficulty walking.

Read the full article at MedlinePlus

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

Convert S83.521D to ICD-9-CMHistory

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

ICD-9-CM
V58.89 Other specfied aftercare
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 S83.521DOverview

Is S83.521D (Sprain of posterior cruciate ligament of right knee) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report sprain of posterior cruciate ligament of right knee, subsequent encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character D in S83.521D mean?

The final character D marks a subsequent encounter: use it for routine care while the sprain of posterior cruciate ligament of right knee is healing, after active treatment has ended.

What MS-DRG does S83.521D group to?

When sprain of posterior cruciate ligament of right knee, subsequent encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 949, 950, with relative weights from 0.6277 to 1.1897 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S83.521D 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 sprain of posterior cruciate ligament of right knee, subsequent encounter on inpatient claims.

What is the ICD-9 equivalent of S83.521D?

Under the General Equivalence Mappings, sprain of posterior cruciate ligament of right knee, subsequent encounter converts to ICD-9-CM V58.89 (other specfied aftercare). 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.