2026 ICD-10-CM Diagnosis Code T84.031SMechanical loosening of internal left hip prosthetic joint, sequela

ICD-10-CM CodesS00–T88T80-T88T84

ICD-10-CM T84.031S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T84.031S is a billable ICD-10-CM diagnosis code for mechanical loosening of internal left hip prosthetic joint, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 922 through 923. The code is exempt from POA reporting. Coders also document this condition as loosening of hip joint prosthesis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complication, sequela.

Code Identity

ICD-10-CM Code
T84.031S
Billable Status
Yes — Valid for Submission
Code Describes
Mechanical loosening of internal left hip prosthetic joint, sequela
Short Description
Mech loosening of internal left hip prosth joint, sequela
Parent Code
Mechanical loosening of internal left hip prosthetic joint

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT80-T88Complications of surgical and medical care, not elsewhere classified
CategoryT84Complications of internal orthopedic prosthetic devices, implants and grafts
This CodeT84.031SMechanical loosening of internal left hip prosthetic joint, sequela

Present on Admission (POA)Billing

T84.031S 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.

  • Loosening of hip joint prosthesis
  • Loosening of left hip joint prosthesis

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Complications of internal orthopedic prosthetic devices, implants and grafts (T84). 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 INJ076
Complication, sequela
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Hip Replacement

Hip replacement is surgery for people with severe hip damage. The most common cause of damage is osteoarthritis. Osteoarthritis causes pain, swelling, and reduced motion in your joints. It can interfere with your daily activities.

Read the full article at MedlinePlus

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

Convert T84.031S to ICD-9-CMHistory

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

ICD-9-CM
909.3 Late eff surg/med compl
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 T84.031SOverview

Is T84.031S (Mechanical loosening of internal left hip prosthetic joint) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report mechanical loosening of internal left hip prosthetic joint, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in T84.031S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the mechanical loosening of internal left hip prosthetic joint itself has resolved, not the original event.

What MS-DRG does T84.031S group to?

When mechanical loosening of internal left hip prosthetic joint, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.

Is T84.031S 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 mechanical loosening of internal left hip prosthetic joint, sequela on inpatient claims.

What is the ICD-9 equivalent of T84.031S?

Under the General Equivalence Mappings, mechanical loosening of internal left hip prosthetic joint, sequela converts to ICD-9-CM 909.3 (late eff surg/med compl). The mapping is approximate, so confirm the match fits the documentation.