The survival rates of children with chronic degenerative disorders have increased as a result of improved treatment options and care methods. As survival rates have improved, the number of children living with chronic diseases has also risen, and the lifestyles of families and children have changed (Yuksel and Yardımcı, 2019). Those children and their families, trying to cope with childhood developmental crises and chronic disease management, interact intensively with pediatric care teams and should be considered specialized team members. It is challenging for children and adolescents to successfully navigate developmental transitions and achieve medical and personal independence.

The purpose of going through the transition process for adolescent patients with special health care needs to adult care is to ensure that individuals receive continuous quality and developmental age-appropriate health care services as they move from adolescence to adulthood, and that the individual's lifelong functioning and potential are maximized (Votroubek and Tabacco, 2020).

Every year, an estimated 500,000–750,000 adolescents with chronic diseases in the United States switch from pediatric to adult care (Tilton, 2018). On the other hand, adult services differ from those for children in terms of care and service. Adult services may be insufficient to meet the psychosocial and developmental needs of adolescent patients with a different approach, a different care plan and a different care team than those adolescent patients and their parents are accustomed to (Fourmaux et al., 2021) and Osborne et al. (2020). These inadequacies increase adolescent patients’ resistance to transitioning to adult services. As a result, the transition from pediatric to adult care is a major health concern, and facilitating the transition lies at the heart of nursing care (Fegran et al., 2014).

Transitional care is defined in the literature as “an active and multifaceted process in which the young person with a chronic illness acquires purposeful and planned behaviors to maintain optimal health and well-being, requiring psychosocial and educational support in addition to medical treatment” (Campbell et al., 2016; Ladores, 2015; Tilton, 2018).

The goal of planned transitional care is to maximize the lifelong function and well-being of all adolescents and young adults, including those with and without special health care needs (Cooley et al., al.,2011).

This study's conceptual framework is based on Uncertainty in Illness Theory (UIT) and Transition Care Theory. In 1981, Merle Mishel created the (UIT) to characterize and explain the uncertainty that patients frequently experience (Mishel, 2015). In the Uncertainty of Illness Theory, which is an intermediate level theory, uncertainty is defined as the inability to determine the meaning of events related to the disease. According to the assessment process, uncertainty is perceived as either an opportunity or a threat. For adolescent patients with multiple sclerosis, the transition process from the pediatric clinic to the adult clinic is adversely affected by the presence of chronic disease in adolescence and its complex and challenging treatment, the occurrence of depression, anxiety, and eating disorders, and the high risk of adolescents’ tendency to engage in risky behaviours (Bora and Buldukoglu, 2020; Cadario et al., 2009; Meleis, 2010).

When we look at the literature, we see several studies examine the impact of the health care transition process on adolescents and young adults (Sheehan et al., 2015). We observe that studies on the transition are being undertaken with adolescent and young adult patients with type 1 diabetes, spina bifida, epilepsy, sickle cell anemia, and juvenile idiopathic arthritis (JIA) (Baca et al., al.,2018; Chu et al., 2015; Crowley et al., 2011; Clemente et al., 2016; Kızıler et al., 2018). When a transition that meets developmental needs and supports autonomy is not provided, 46% of adolescent patients experience difficulty and disappointment in the transition process, 27% of them change adult physicians within the first two years, 58% of them recall the transition period as a poor experience, and 11–41% of them discontinue diabetes care and control after the last pediatric check-up (Cadario et al., 2015).

Multiple sclerosis (MS) is a chronic and degenerative disease. Pediatric patients with multiple sclerosis (diagnosed < 18 years old) account for 3.5%−5% of all patients with multiple sclerosis (Chitnis et al., 2018; Hebert et al., 2019; Spiro, 2012; Ünsal, 2019). The incidence of pediatric multiple sclerosis has been reported to be 0.2 - 0.64 / 100,000 (Reinhardt et al., 2014). No study has been found in the literature on the transition of adolescents with MS from pediatric clinic to the adult clinic in the literature. It is considered that the result of the research will be evidence-based data about the experiences of patients diagnosed with MS while transitioning from pediatric services to adult services.

The aim of this qualitative study is to describe the experiences and expectations of patients between the ages of 18–24 and diagnosed with multiple sclerosis before the age of eighteen in their transition from pediatric care to adult care, as well as their experiences and expectations in the pediatric care process