Organ Transplantation: How the Process Works

This page explains how transplantation works before and during surgery. For anti-rejection medicines, warning signs and life after surgery, see organ transplant.

Which organs are transplanted and why

Tissue transplants such as corneas, bone and skin, and stem cell (bone marrow) transplants, follow different processes.

Who qualifies for a transplant

You are usually referred when your organ disease is advanced and expected to shorten life or severely limit it, and you are well enough to survive major surgery and take lifelong medicines. Each center has its own criteria, but common reasons a transplant may be delayed or not possible include:

• Active cancer, or recent cancer that is likely to return
• Active, uncontrolled infection
• Severe disease of another organ that makes surgery too risky
• Active alcohol or drug use (centers often require a period of sobriety and treatment)
• Inability to take medicines reliably, or no support network
• Severe frailty or, at some centers, very high BMI

Age alone does not exclude people; many recipients are in their 70s.

The transplant evaluation

A team of surgeons, specialists, nurses, a social worker, a dietitian, a financial coordinator and often a psychologist or pharmacist meets you. Tests typically include:

• Blood type, tissue typing (HLA) and antibody screening
• Heart tests such as an ECG, echocardiogram and stress test or angiogram
• Imaging of the organ and blood vessels
• Infection screening: HIV, hepatitis B and C, CMV, EBV, tuberculosis
• Age-appropriate cancer screening, dental checks, and vaccination updates
• Psychosocial and financial review, including who will be your caregiver

The committee then decides whether to list you, asks for more tests or treatment first, or explains why transplant is not suitable.

The waiting list and how matching works

In the US, the Organ Procurement and Transplantation Network (OPTN) runs the national waiting list under federal oversight. When a deceased donor organ becomes available, a computer generates a ranked list of compatible candidates. Factors include:

• Blood type and body size compatibility
• Tissue type and antibodies: a crossmatch test checks that the recipient has no antibodies against the donor
• Medical urgency: the MELD score (or PELD for children) for liver; urgency status tiers for heart; a composite score for lung
• Time on the waiting list, especially for kidneys, where time counts from the start of dialysis or from listing with low kidney function
• Distance between donor and transplant hospital, because organs can only be stored for limited hours

Race, income and celebrity status are not used. People with high antibody levels, or blood type O or B, often wait longer.

Living donation

A healthy person can donate one kidney or part of the liver. Living donor organs usually work sooner and last longer than deceased donor organs. Donors go through their own evaluation, have an independent advocate, and can withdraw at any time. If a willing donor is not compatible, paired kidney exchange programs swap donors between pairs.

The surgery

When an organ is offered, you are called in, examined and given a final crossmatch. Surgery usually takes 3 to 4 hours for a kidney and 6 to 12 hours for a liver, heart or lung. A transplanted kidney is placed low in the abdomen and the old kidneys are usually left in place. Hospital stays range from about 3 to 7 days for a kidney to several weeks for lung or heart transplants.

Anti-rejection (immunosuppressive) medicines start around the time of surgery and continue for life. Long-term steroid use can cause complications such as diabetes and bone thinning, which teams try to minimize.

Survival and outcomes

• Kidney: over 90% of transplanted kidneys work at 1 year. Living donor kidneys commonly last 15 to 20 years, deceased donor kidneys 10 to 15 years on average. Transplant lets most people live longer and better than on dialysis.
• Liver and heart: around 9 in 10 recipients survive the first year, and many live 10 to 20 years or more.
• Lung: outcomes are lower, with median survival around 6 years, mainly due to chronic rejection.

Becoming an organ donor

Most donated organs come from people who die in hospital on a ventilator, from brain death or circulatory death. One donor can save up to 8 lives. You can register through your state registry or driver's license office, and should tell your family your wishes.

Frequently asked questions

How long is the waiting list for an organ transplant?

It varies widely. Median kidney waits are several years in many regions, longer for people with blood type O or high antibody levels. Liver, heart and lung waits depend mostly on how sick you are, ranging from days for the most urgent to months or longer. A living donor can shorten the wait for a kidney or liver.

Who decides who gets an organ?

In the US, organs from deceased donors are allocated by national OPTN policies using a computer match. Ranking depends on medical compatibility, urgency, waiting time and distance. The transplant surgeon then decides whether the specific organ is suitable for the patient at the top of the list.

Can you get a transplant if you are older?

Often, yes. There is no strict upper age limit at most centers, and people in their 70s receive kidney and liver transplants. What matters is overall fitness, heart health, frailty and the ability to recover from surgery and take anti-rejection medicines.

Is a living kidney donation safe for the donor?

For carefully screened healthy donors, it is considered safe. Surgery is usually done by keyhole technique, recovery takes a few weeks, and the remaining kidney increases its function. There is a small lifetime increase in kidney failure risk, which is assessed during the donor evaluation.

Does insurance cover organ transplantation?

Medicare, Medicaid and most private insurers cover transplants that meet their criteria, though out-of-pocket costs for travel, lodging and lifelong medicines can be large. Medicare covers kidney transplants for people with kidney failure, and recent law extended coverage of anti-rejection drugs. Each center has a financial coordinator to help.