Comprehensive Care for Joint Replacement Model

On April 29, 2021, CMS issued a final rule (PDF) in the Federal Register to extend and change the CJR Model. See Regulations & Notices section below for additional information.

The Comprehensive Care for Joint Replacement (CJR) Model is designed to improve care for Medicare patients undergoing hip and knee replacements (also called lower extremity joint replacements or LEJR) performed in the inpatient or outpatient setting and for total ankle replacements performed in the inpatient setting.  Hip and knee replacement are the most common surgeries for Medicare beneficiaries and by providing participating hospitals with bundled payments for these procedures, as well as ankle replacements, the CJR Model encourages hospitals, physicians, and post-acute care providers to work together to improve the quality and coordination of care from the initial hospitalization or outpatient procedure through recovery. The CJR Model became mandatory in October 2021, and is implemented and modified through notice and comment rulemaking (relevant final rules are linked under “Additional Information” below). The model began on April 1, 2016 and will run through December 31, 2024, representing eight performance years (PYs).

Please find in the ‘Additional Information’ section at the bottom of this page, a short video describing the CJR Model and the findings of the third Evaluation Report.


  • Hip, knee, and ankle replacements, also known as lower extremity joint replacements, are the most common surgeries Medicare beneficiaries receive. Many patients experience confusing, uncoordinated care before and after their surgery, which can lead to complications or prolonged recovery.
  • In the Comprehensive Care for Joint Replacement (CJR) Model, participating hospitals take on additional responsibilities for patients undergoing a lower extremity joint replacement. These include ensuring that patients receive high-quality, coordinated care by all health care providers from the time of the procedure through recovery, including physical therapy and any other at-home rehabilitation care. Providers work with their patients to develop a plan for recovery, including whether they prefer to recover at home instead of a rehabilitation facility.
  • The goal of the CJR model is for patients to have a safe, effective, and positive recovery experience that is free from complications, while maintaining their freedom of choice in providers and services.

Model Design

The CJR Model is a Medicare Part A and B payment model that holds participant hospitals financially accountable for the quality and cost of a CJR episode of care and incentivizes increased coordination of care among hospitals, physicians, and post-acute care providers. A CJR episode is defined by the admission of an eligible Medicare fee-for-service beneficiary to a hospital paid under the Inpatient Prospective Payment System (IPPS) that eventually results in a discharge paid under:

  • MS-DRG 469 (Major Hip and Knee Joint Replacement or Reattachment of Lower Extremity with Major Complications or Comorbidities (MCC), 
  • MS-DRG 470 (Major Hip and Knee Joint Replacement or Reattachment of Lower Extremity without MCC), 
  • MS-DRG 521 (Hip Replacement with Principal Diagnosis of Hip Fracture with MCC), or 
  • MS-DRG 522 (Hip Replacement with Principal Diagnosis of Hip Fracture without MCC). 

To address the removal of the Total Knee Arthroplasty (TKA) and Total Hip Arthroplasty (THA) from the inpatient-only (IPO) list in calendar year 2018 and calendar year 2020 respectively, CMS changed the definition of an ‘episode of care’, beginning in PY6, to include outpatient (OP) procedures for TKAs (OP TKAs) and THAs (OP THAs), in addition to inpatient procedures. For all episodes, the episode of care continues for 90 days following discharge from the inpatient hospitalization or the date of the outpatient procedure.

With few exceptions, the episode includes all related items and services paid under Medicare Part A and Part B for eligible CJR patients. The complete list of exclusions can be found below as well as the list of excluded MS-DRGs and ICD-10-CM diagnosis codes. 

Performance Years

The performance years for the CJR Model are:     

  • PY 1: April 6, 2016-December 31, 2016
  • PY 2: January 1, 2017-December 31, 2017 
  • PY 3: January 1, 2018-December 31, 2018 
  • PY 4: January 1, 2019-December 31, 2019 
  • PY 5.1: January 1, 2020-December 31, 2020 
  • PY 5.2: January 1, 2021-September 30, 2021 
  • PY 6: October 1, 2021-December 31, 2022 
  •  PY 7: January 1, 2023-December 31, 2023 
  •  PY 8: January 1, 2024-December 31, 2024 


The CJR model was originally implemented in 67 metropolitan statistical areas or MSAs. By definition, MSAs are counties associated with a core urban area that has a population of at least 50,000. Non-MSA counties (no urban core area or urban core area of less than 50,000 population) were not eligible for selection. For the first two performance years, hospitals paid under IPPS and located in the 67 MSAs, with few exceptions, were required to participate. As of February 1, 2018, IPPS hospitals in 34 of the original 67 MSAs were required to participate, expect for participant hospitals categorized as low volume or rural hospitals. Participant hospitals in the other 33 original MSAs, were given a one-time opportunity to voluntarily opt in to the CJR model during January 2018 for PYs 3 through 5. As of October 1, 2021, only hospitals in one of the 34 required MSAs and not designated as low volume or rural are required to participate in the CJR model 3-year extension. As a result, there are approximately 324 participant hospitals actively participating in the CJR model for PYs 6 through 8. The list of CJR participant hospitals is available below.

In the CJR model, beneficiaries retain their freedom of choice to choose services and providers. Physicians and hospitals are expected to continue to meet the current standards required by the Medicare program. All existing safeguards to protect beneficiaries and patients remain in place. If a beneficiary believes that his or her care is adversely affected, he or she should call 1-800-MEDICARE or contact their state’s Quality Improvement Organization by going to The points of contact should be individuals employed by the hospital that would be the best people for CMS to reach out to with instructions for receiving data and other technical issues.


The CJR model is a retrospective bundled payment model where CMS provides participant hospitals with a target price for each CJR MS-DRG, prior to the start of each performance year. All providers and suppliers furnishing LEJR episodes of care to patients throughout the year are paid under existing Medicare payment systems. The target price includes a discount over expected episode spending and initially incorporated a blend of historical hospital-specific spending and regional spending for LEJR episodes, with the regional component of the blend increasing over time and eventually being 100 percent regional for PYs 4 through 8. 

Following the end of a model performance year, actual total spending for the episode is compared to the target price for the participant hospital where the beneficiary had the initial LEJR surgery. Depending on the participant hospital’s quality and episode spending performance, the hospital may receive an additional payment from Medicare or be required to repay Medicare for a portion of the episode spending.

Quality Measures

The CJR model has the potential to improve quality in three ways:

  1. The model adopts a quality first principle, meaning hospitals must achieve a minimum level of episode quality, as determined by a hospital’s composite quality score, before receiving reconciliation payments. 
    • The composite summary score reflects hospital performance and improvement on the following two measures: Hospital-Level Risk-Standardized Complication Rate (RSCR) Following Elective Primary Total Hip Arthroplasty (THA) and/or Total Knee Arthroplasty (TKA) measure (NQF#1550); and Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) Survey measure (NQF#0166). 
    • The composite quality score also considers a hospital’s submission of THA/TKA patient-reported outcomes and limited risk variable voluntary data. Specifically, for PYs 6 through 8, the thresholds for the patient reported outcome measures are loosened to promote the successful submission of data as participant hospitals gain experience with patient reported outcome data. 
  2. Second, the model incentivizes hospitals to avoid expensive and harmful events, which increase episode spending and reduce the opportunity for reconciliation payments.
  3. Third, CMS provides additional tools to improve the effectiveness of care coordination by participant hospitals in selected MSAs. These tools include: 
    • providing hospitals with relevant spending and utilization data;
    • waiving certain Medicare requirements to encourage flexibility in the delivery of care; and
    • facilitating the sharing of best practices between participant hospitals through a learning and diffusion program. 

How to Contact the CJR Model Team

If you have questions regarding the Model, you can contact the CJR model team by emailing

Additional Information

Regulations & Notices

Interim and Proposed Rules

Final Rules

Fact Sheets

Participant Resources

List of Participant Hospitals


Target Prices and Risk Adjustment

Reconciliation Results and Quality Measures

SNF Lists

Beneficiary Notification Letters


Evaluation Reports

Latest Evaluation Report

Prior Evaluation Reports

Where Health Care Innovation is Happening