ABSTRACT Background: More than 95% of people with Down syndrome develop Alzheimer Disease (AD), with median age of onset of 54 years. However, there is a significant gap in guidance around the design of effective memory services and tailored diagnostic pathways. Objective: To identify and describe existing memory service models and dementia diagnostic pathways for adults with Down syndrome. Methods: A scoping review was conducted according to the Joanna Briggs Institute’s updated methodological guidance for scoping reviews. Four databases (Ovid MEDLINE, Ovid EMBASE + EMBASE Classic, Ovid PsycINFO and EBSCO CINAHL Plus) were searched using three key concepts: Alzheimer Disease, Down syndrome and Memory Service. All primary study types were included from January 1, 2005 to March 2026. Results: Fifty-five studies were identified, 16 relevant studies included after screening: 11 service evaluations, two prospective cohorts, one observational and two qualitative research studies. Twelve were UK based. Memory services were multidisciplinary with a mixture of baseline and prospective screening for AD Conclusions: There is limited literature describing dedicated memory services and dementia diagnostic pathways for people with Down Syndrome. Existing services highlight features including multidisciplinary team involvement, baseline and prospective cognitive screening, and the longitudinal use of validated screening tools.