People with developmental disabilities who are in need of life-saving organ transplants are facing widespread discrimination from health care providers, a new report indicates.

In what’s believed to be the first comprehensive look at the experiences of those with intellectual and developmental disabilities seeking transplants, advocates found that individuals are routinely turned down for the procedures due to their special needs.

The report released this week by the Autistic Self Advocacy Network indicates that doctors often weigh the presence of a developmental disability when making decisions about transplant eligibility, but to what degree varies largely depending on the type of organ needed. Evidence suggests that many heart transplant centers consider a cognitive impairment reason enough to make the procedure inadvisable, while disabilities are generally less of a driving factor in determinations related to liver and kidney transplants, for example.

Federal law prohibits health care providers from discriminating on the basis of a person’s disability. Nonetheless, the report finds that given the broad discretion that doctors have in making medical judgements “decision-making done on the basis of disability can often be officially attributed to non-discriminatory motives.”

In other cases, doctors have expressed concerns about the ability of patients with disabilities to appropriately handle their postoperative care.

The report comes on the heels of two high-profile cases last year involving individuals with developmental disabilities who were denied transplants. In one instance, 3-year-old Amelia Rivera, diagnosed with intellectual disability and Wolf-Hirschhorn syndrome, was ultimately granted approval for a kidney transplant amid public outrage. But doctors stuck to their decision not to grant a heart transplant to Paul Corby, a 23-year-old with autism.

Now, advocates are urging federal health officials to issue guidance to the nation’s transplant centers on their obligations to serve people with disabilities. Representatives from the Autistic Self Advocacy Network, Not Dead Yet and the National Disability Rights Network met with leaders of the U.S. Department of Health and Human Services’ Office for Civil Rights this week to plead their case.

“Right now we have a situation where discrimination is the norm in accessing organ transplants for people with disabilities, so action is very much in order,” said Ari Ne’eman, president of the Autistic Self Advocacy Network. “I think we have a real commitment on the part of HHS.”