Addressing the Gaps in Kidney Transplantation with the IOTA Model

In 2022, with 25,000 kidney transplants performed in the U.S., nearly 90,000 individuals remained on a transplant waitlist while 26% of retrieved organs went unused that same year. With transplantation regarded as the best treatment for end-stage renal disease (ESRD) and a growing demand of 3,000 patients added to waitlists per month, there is a need to optimize organ use. 

In order to address the growing demand for kidney transplants in the US and improve patient access, the Centers for Medicare & Medicaid Services (CMS) introduced the Increasing Organ Transplant Access (IOTA) Model. The model aims to incentivize kidney transplant hospitals to increase transplant volume and efficiency while maintaining high-quality care.

What is the IOTA Model?

The IOTA Model is a six-year mandatory payment model effective from July 1, 2025 through June 30, 2031 with the aim to increase access to life-saving kidney transplants and improve health outcomes for patients living with kidney disease. The model design supports greater care coordination and improves patient-centeredness for patients who are waiting for a transplant and those who receive a transplant.

Image Source | CMS Fact Sheet

The IOTA Model provides incentives to promote the following goals and objectives:

• Improve quality of care in kidney transplants before, during, and after transplantation;
• Maximize the use of deceased donor kidneys;
• Identify more living donors and assist potential living donors through the donation process;
• Create greater access to a kidney transplant by addressing social determinants of health and other barriers to care;
• Improve care coordination and patient-centeredness in the kidney transplant process; and
• Reduce Medicare expenditures.

To achieve these goals model participants are incentivized to increase their transplant rates for all groups of people including those population groups that experience disparities in access.

The model uses one-sided risk in Performance Year (PF) 1 and two-sided risk beginning in PY2. Based on a hospital’s final performance scores, a hospital will receive the regular fee-for-service (FFS) payment and either a payment from CMS, owe a payment to CMS, or neither receive or owe a payment.  The maximum additional payment from CMS is $15,000 per Medicare FFS transplant. The maximum payment owed to CMS is $2,000 per Medicare FFS transplant.

Eligibility Criteria

To qualify for selection, hospitals needed to perform at least 11 adult kidney transplants annually during the baseline period (CY 2021–2023), regardless of payer type. Additionally, at least half of their annual kidney transplant volume had to involve patients 18 or older.

In order to decrease regional disparity in organ supply, CMS selected half of the donation service areas (DSAs) through a stratified random sampling.  All non-pediatric kidney transplant hospitals in those DSAs that meet the volume criteria are required to participate, for a total of 103 kidney transplant hospitals. The remaining hospitals serve as a comparison group for evaluation. The selected hospitals will operate within a framework that incorporates upside and downside risk payments based on performance.

Download the list of mandated CMS hospitals participating here: list of participating kidney transplant hospitals (XLSX).

Performance Assessment

Hospital performance is scored based on a 100 point maximum across three domains: 

• Achievement (60 points): Number of kidney transplants performed relative to a hospital-specific target.
• Efficiency (20 points): Kidney organs offer acceptance rates relative to the national rate.
• Quality (20 points): Assessed using post-transplant outcomes based on the hospital’s composite graft survival rate.

Source: CMS Fact Sheet

Each hospital’s performance score across these three domains determines its final performance score and corresponding amount for the upside risk payment that will be paid to the hospital. The upside payment is a lump sum payment paid at the end of the performance year for any hospital with a score of 60 or greater.

Achievement Domain (60 point)

The Achievement domain measures the number of kidney transplants performed relative to a hospital-specific target. The Transplant Target methodology is determined based on the sum of the averages of living and deceased donor kidney transplant volumes during the three baseline years. This calculation is aimed at reflecting the potential maximum capacity of the participant hospital and is adjusted for volume growth rates. The Achievement score is then calculated based on the hospital’s actual volume compared to the Transplant Target.

Based on comments received during the proposed ruling review, CMS introduced an updated scoring system with a lower maximum performance threshold of 125%, aiming to better differentiate participants by increasing performance bands from five to eight. These narrower bands allow for more precise comparisons across hospitals (Source: Final Rule Table 4).

Efficiency Domain (20 point)

The Efficiency domain measures the hospital’s kidney Organ-Offer Acceptance Rate Ratio (OARR), by dividing the number of kidneys the hospital accepted by a risk-adjusted number of expected organ-offer acceptances using SRTR’s methodology. 

Scoring for the OARR is based on the higher of the Achievement Score and the Improvement Score. 

• Achievement Score: Reflects the hospital’s OARR relative to a national ranking as seen in Table 7.
• Improvement Score: Compares the hospital’s OARR to the hospital’s Improvement Benchmark Rate. See Equation 4 to calculate the Improvement Scoring for OARR. 

Source: Final Rule Table 7

Quality Domain (20 point)

The Quality domain assesses the quality of care provided by the participating hospital utilizing a composite graft survival ratio measuring post-transplant outcomes relative to the composite graft survival rate across all kidney transplant hospitals. In the first performance year the composite graft survival rate is calculated for a participating hospital by dividing the cumulative number of all functioning kidney grafts by the total number of kidney transplants performed. In following years this number will be updated to account for any failed transplants in previous years. The following are excluded from the number of functioning grafts:

• Graft Failure
• Retransplant
• Death
• Pediatric patients, and
• Offers to multi-organ candidates with the exception of kidney/pancreas candidates

(Source:Federal Register Final Rule)

Quality domain scoring is based on how a participant performed against all eligible hospitals regardless if they were selected for participation in the IOTA model. 

Source: Final Rule Table 9

CMS had initially proposed to require IOTA participants to report three quality measures utilizing patient-reported outcome measures (PROMs) in transplant care, but after receiving comments, none were finalized. In future rulemaking, CMS may propose an expanded quality measure set for kidney transplants, focusing on health-related quality of life (HRQoL) and  pre-transplant care process.

Payment Structure

The IOTA model final rule includes both upside and downside financial risks in addition to the normal Medicare fee-for-service (FFS) payments. Upside payments to the participating hospital and downside payments to CMS will be determined by the volume of transplants where Medicare was the primary or secondary payer. However, scoring metrics are based on all eligible patients regardless of payer type.

Upside Risk Payments

Participants with a final performance score of 60 or above are eligible for an upside risk payment which could be up to $15,000 per Medicare FFS kidney transplant. The actual upside risk payment value is calculated as $15,000 x ((final performance score – 60)/40) x total number of kidney transplants performed where Medicare is the primary or secondary payer.

Neutral Zone

For participants that have a final performance score below 60 in the first performance year and scores between 41 and 59 in following years they will be placed in a neutral zone. Participants in the neutral zone will neither receive payments outside of the normal Medicare FFS nor be required to pay CMS.

Downside Risk Payment

Participants with a final performance score below 40 points in performance years 2 through 6 will be required to pay CMS a downside risk payment with a maximum payment of $2,000 per Medicare FFS kidney transplant. The actual downside risk payment value is calculated as $2000 x ((40 – final performance score)/40) x the total number of kidney transplants performed where Medicare is the primary or secondary payer.

Payment System and Model Overlaps

The IOTA Model is expected to overlap with other CMS programs, such as the Kidney Care Choices (KCC) Model and the End-Stage Renal Disease Treatment Choices (ETC) Model, potentially leading to hospitals participating in multiple Advanced Payment Models (APMs) with overlapping incentives. CMS has allowed IOTA participants to engage concurrently in IOTA and other CMS Innovation Center models or CMS programs. The IOTA Model finalized rule removes previous Medicare reapproval requirements for transplant hospitals, including data submission and outcomes metrics.

Data Sharing and Monitoring

To increase transparency for beneficiaries, CMS requires IOTA participants to publish on a public website the criteria they use to determine whether or not a patient is added to the kidney transplant waitlist. 

CMS has also finalized a proposal to share beneficiary-identifiable data with IOTA participants to help improve transplant readiness, post-transplant outcomes, and overall care coordination. This data will include beneficiary claims information for Parts A, B, and D claims data. This data will be used by participants to evaluate performance, conduct quality assessments, and coordinate care across various providers. IOTA participants must comply with the Health Insurance Portability and Accountability Act of 1996 (HIPAA) and sign a data-sharing agreement to protect patient privacy and confidentiality.

Medicare beneficiaries will be notified of the data sharing and be given the opportunity to opt out. Although patients can opt-out of identified data sharing, they cannot opt out of de-identified data sharing. 

As part of the IOTA Model, CMS includes monitoring and compliance practices to ensure model integrity and to safeguard patient care. These monitoring activities include documentation requests, data audits, patient interviews, and site visits to ensure adherence to model terms. 

Conclusion

The finalized IOTA Model represents advancement in developing a sustainable Medicare payment model for kidney transplants, improving access, efficiency, and equity of care in the US. By incentivizing transplant hospitals to increase volume, improve organ offer acceptance rates, and maintain high-quality care, the model aims to improve patient outcomes and reduce disparities. Continued collaboration among stakeholders and careful monitoring will be crucial for the successful implementation and evaluation of this important program.