OPTN allocation policy

OPTN allocation policy is the body of rules that governs how deceased-donor organs are offered to transplant candidates in the United States. The policies are written by the Organ Procurement and Transplantation Network (OPTN) through its Board of Directors and organ-specific committees, bounded by the federal OPTN Final Rule (42 CFR Part 121), and are carried out operationally as a computerized match run that ranks candidates for each available organ using only medical and logistical factors.[1][2][3] Allocation policy is organ-specific: liver candidates are ranked principally by the MELD / MELD 3.0 urgency score, kidney candidates by a combination of waiting time, sensitization, donor quality, and longevity matching, lung candidates by a Composite Allocation Score, and heart candidates by a multi-tier urgency status system.[2][3]

The legal foundation for allocation policy is the National Organ Transplant Act (NOTA) of 1984, which created the OPTN, and the Final Rule promulgated under it, which requires that allocation be based on sound medical judgment and equitable access rather than on a candidate's place of residence or place of listing.[1][3] This article describes the policy-making framework, the federal constraints, and the principal organ-specific systems; the mechanics of producing a ranked candidate list are described in The match run.

Legal and regulatory basis

The OPTN Final Rule (42 CFR Part 121)

OPTN policy operates within the OPTN Final Rule, a set of federal regulations issued by the U.S. Department of Health and Human Services (HHS) and codified at 42 CFR Part 121.[1][3] The Final Rule was first published in 1998 and took effect in 2000; it sets the framework within which the OPTN develops allocation policy and provides for HHS oversight of that policy.[1][3] The portion of the Final Rule governing allocation, 42 CFR §121.8, requires that the OPTN Board develop organ-allocation policies that:[1]

• shall be based on sound medical judgment;
• shall seek to achieve the best use of donated organs;
• shall preserve a transplant program's ability to decline an offer;
• shall be specific for each organ type or combination of organ types;
• shall be designed to avoid wasting organs, to avoid futile transplants, and to promote patient access to transplantation;
• shall be reviewed periodically and revised as appropriate;
• shall include procedures to promote and review compliance; and
• "shall not be based on the candidate's place of residence or place of listing," except to the extent that geography is required by the medical and best-use criteria above.[1]

The Final Rule further directs (in §121.8(b)) that allocation policies be designed to achieve equitable allocation of organs among patients, using standardized criteria, priority rankings expressed "to the extent possible, through objective and measurable medical criteria," and distribution over "as broad a geographic area as feasible" consistent with sound medical judgment and the efficient use of organs.[1] These provisions are the legal reason that modern allocation policy has moved away from rigid geographic units toward broader sharing and toward continuous distribution, described below and in Geographic distribution and acuity circles.[1][4]

NOTA and the OPTN contract

NOTA established the OPTN and required that it be operated by a private, nonprofit entity under federal contract.[5] The United Network for Organ Sharing (UNOS) has held that contract continuously since 1986; under the OPTN modernization initiative begun in 2023, HHS and the Health Resources and Services Administration (HRSA) have moved toward a multi-vendor model with an independent OPTN board, but the policy-making framework described here is unchanged.[3][5] Federal law and the Final Rule make HHS the ultimate authority over OPTN policy: the Secretary may direct the OPTN to revise a policy, and OPTN policies that have been formally adopted are binding on member transplant hospitals, organ procurement organizations, and histocompatibility laboratories.[1][3]

How allocation policy is made

OPTN allocation policy is developed through a structured, public process rather than by regulation alone.[2][3] Organ-specific committees (for example, the Kidney Transplantation, Liver and Intestinal Organ Transplantation, Thoracic Organ Transplantation, and Pancreas Transplantation committees), supported by data analyses from the OPTN contractor and the Scientific Registry of Transplant Recipients (SRTR), draft proposed policy changes.[2][3] Proposals are released for a defined public comment period during which transplant professionals, patients, donor families, and the public may respond; the committees then revise the proposals and forward them to the OPTN Board of Directors for a vote.[2][3] Adopted policies are published in the OPTN Policies document, which is the canonical, dated source for the rules in force, and are implemented in the national computer system after a programming and notice period.[2][3]

This deliberate, evidence-and-comment process is why major allocation changes are dated events: the move to liver acuity circles (2020), the removal of the donation service area and region from kidney and pancreas allocation (2021), the move of lung allocation to continuous distribution (2023), and the adoption of MELD 3.0 (2023) each followed this pathway.[2][4]

The match run

OPTN allocation policy is executed through the match run: when an organ procurement organization enters a deceased donor's clinical and laboratory data into the national computer system, the system applies the relevant organ-specific policy and generates a rank-ordered list of candidates for each organ.[2][6] The match run is unique to each donor and each organ, and organs are offered to transplant programs in the order the policy produces.[2][6] Because the match run mechanically applies the policy, the factors a candidate is ranked by are exactly the factors that policy permits: blood-type compatibility, medical urgency, waiting time, body size, immune sensitization, pediatric status, prior living-donor status, and distance from the donor hospital, among others, depending on the organ.[2][6] Per the Final Rule, those factors are medical and logistical; the candidate's place of residence or listing is not itself a ranking factor except where geography is medically necessary.[1][2]

Organ-specific allocation systems

Because §121.8 requires policy to be "specific for each organ type," the OPTN maintains a distinct allocation system for each organ.[1][2]

Kidney and pancreas

Deceased-donor kidney allocation combines waiting time (which begins at the start of dialysis or at listing with low kidney function), immune sensitization measured by calculated panel-reactive antibody (cPRA), blood-type compatibility, pediatric priority, prior living-donor priority, and longevity matching, which uses the Kidney Donor Profile Index (KDPI) to describe donor quality and the Estimated Post-Transplant Survival (EPTS) score to identify candidates expected to benefit longest, so that the longest-functioning kidneys are offered preferentially to candidates with the longest expected post-transplant survival.[2][7] Since 2021, kidney and pancreas allocation no longer uses the donation service area or OPTN region as a unit; organs are first offered within a fixed distance of the donor hospital, as described in Geographic distribution and acuity circles.[4]

Liver and intestine

Adult liver candidates are prioritized chiefly by medical urgency, measured by the Model for End-Stage Liver Disease (MELD) score, in its current form MELD 3.0, adopted in 2023; pediatric candidates use the Pediatric End-Stage Liver Disease (PELD) score.[8][9] A small number of candidates with very high short-term mortality (for example, acute liver failure) qualify for the highest-urgency Status 1A/1B categories.[8] Liver allocation has used fixed-distance acuity circles since 2020.[8] See MELD / MELD-Na / MELD 3.0 (and PELD).

Heart

Adult heart candidates are ranked by a six-status urgency system adopted in 2018, which replaced an earlier three-tier system to better stratify the most urgent candidates, including those supported by mechanical circulatory support devices.[10] See Heart allocation status system.

Lung

Lung allocation was the first organ system to move to continuous distribution, effective March 9, 2023, replacing the Lung Allocation Score (LAS) with a Composite Allocation Score (CAS) that combines medical urgency, expected post-transplant outcome, candidate biology, patient access, and placement efficiency into a single weighted score.[4][11] See Continuous distribution and the Composite Allocation Score and Lung Allocation Score (LAS).

Equity and the move away from geography

A recurring theme in OPTN allocation policy is the tension between equity (comparable access for similar candidates regardless of where they live or list) and efficiency / organ quality (minimizing cold-ischemia time and travel).[1][4] The Final Rule's instruction that allocation "shall not be based on the candidate's place of residence or place of listing," combined with litigation and analyses showing geographic disparities in access, drove a multi-year evolution away from the historical donation service area (DSA) and region as allocation units toward fixed-distance acuity circles and, ultimately, toward continuous distribution, which eliminates hard geographic boundaries and instead assigns distance a weighted point value within a composite score.[1][4] As of mid-2026, lung is the only organ live on continuous distribution; kidney, pancreas, liver, intestine, and heart systems are at various stages of development and public comment.[4][11] This evolution is described in detail in Geographic distribution and acuity circles and Continuous distribution and the Composite Allocation Score.

See also

• The match run
• MELD / MELD-Na / MELD 3.0 (and PELD)
• Continuous distribution and the Composite Allocation Score
• Lung Allocation Score (LAS)
• Heart allocation status system
• Geographic distribution and acuity circles
• National Organ Transplant Act (NOTA)
• Organ Procurement and Transplantation Network (OPTN)

References

• 42 CFR §121.8, Allocation of organs (OPTN Final Rule). Legal Information Institute, Cornell Law School. https://www.law.cornell.edu/cfr/text/42/121.8
• UNOS. How we match organs. https://unos.org/transplant/how-we-match-organs/
• Health Resources and Services Administration (HRSA). OPTN modernization and the OPTN. https://www.hrsa.gov/optn-modernization
• HRSA / OPTN. Continuous Distribution. https://www.hrsa.gov/optn/policies-bylaws/policy-issues/continuous-distribution
• National Organ Transplant Act of 1984, Pub. L. 98-507; 42 U.S.C. §274 et seq. https://www.congress.gov/bill/98th-congress/senate-bill/2048
• UNOS. Is it really a list? What determines how organs are allocated. https://unos.org/news/is-it-really-a-list-what-determines-how-organs-are-allocated-and-the-role-unos-technology-plays-in-it/
• HRSA / OPTN. A guide to calculating and interpreting the Kidney Donor Profile Index (KDPI). https://optn.transplant.hrsa.gov/media/1512/guide_to_calculating_interpreting_kdpi.pdf
• HRSA / OPTN. Improving Liver Allocation: General Implementation FAQ. https://optn.transplant.hrsa.gov/media/ehtnanyg/improving-liver-allocation-general-implementation-faq.pdf
• UNOS / OPTN. Updates to medical urgency scoring for liver transplant candidates in effect (MELD 3.0). https://www.hrsa.gov/optn/news-events/news/updates-medical-urgency-scoring-liver-transplant-candidates-effect
• UNOS. Adult heart allocation policy changes (six-status system, 2018). https://unos.org/news/new-adult-heart-allocation-policy-in-effect/
• UNOS / OPTN. New lung allocation policy in effect (lung Composite Allocation Score). https://unos.org/news/new-lung-allocation-policy-in-effect/