The Phelan-McDermid Syndrome Foundation supports individuals affected by Phelan-McDermid syndrome, providing resources, community support, and driving research for treatments and cures.

The Pheo Para Alliance supports individuals affected by pheochromocytoma and paraganglioma through education, research, advocacy, and community support.

The Philippine Society for Orphan Disorders, Inc. is dedicated to improving the lives of patients with rare diseases in the Philippines by providing support, resources, and advocacy.

Pilot Parents of Southern Arizona provides support and advocacy training for families with children who have special needs.

The Pink Rocki Advocacy Foundation focuses on preparing youth for adulthood through programs in self-awareness, wellness, community service, and financial assistance for college-bound students.

The Pituitary Foundation supports individuals with pituitary conditions by providing information, resources, and community events to raise awareness and improve diagnosis and treatment.

The Plasminogen Deficiency Foundation is a non-profit organization dedicated to supporting patients with plasminogen deficiency (PLGD) and their families by providing education, community support, and financial assistance for treatment-related costs.

The Platelet Disorder Support Association (PDSA) is dedicated to providing information and support for individuals affected by immune thrombocytopenia (ITP), offering resources, community connections, and educational materials.

The organization supports the community of polio survivors and provides resources and information on the late effects of polio.

Postpartum Support International provides support and resources for families dealing with perinatal mental health issues, including postpartum depression, and offers training for professionals in the field.

The Prader-Willi Syndrome Association UK provides support and information for individuals affected by Prader-Willi Syndrome, offering resources for care and guidance.

The Prader-Willi Syndrome Association USA supports individuals and families affected by Prader-Willi syndrome through advocacy, awareness, and providing critical resources and information.

The Preeclampsia Foundation focuses on improving outcomes for women and babies affected by hypertensive disorders of pregnancy through education, support, and research.

Prevent Blindness is the nation's leading volunteer eye health and safety organization, dedicated to preventing blindness and preserving sight through education, advocacy, and support for individuals with vision problems.

The PBCers Organization is a support group for individuals affected by Primary Biliary Cholangitis (PBC), providing resources for peer support and information on the disease.

The Progeria Research Foundation is dedicated to discovering treatments and a cure for Progeria, a rare and fatal disease that causes rapid aging in children, and supports affected families through research and clinical trials.

UPMC Children’s Hospital of Pittsburgh is a leader in the treatment of childhood conditions and diseases, providing innovative therapies and education for pediatric care.

PSPA is the only UK charity dedicated to supporting individuals affected by Progressive Supranuclear Palsy and Corticobasal Degeneration through information, support, and research initiatives.

The Project 8p Foundation supports individuals affected by chromosome 8p disorders by raising funds for research and providing a community for families to navigate the challenges associated with these rare diseases.