Hi @ElenaP, the advice I copied is I understand for adults Tandem recommend the approved site is abdomen only, but for children (6-17) the approved sites are the abdomen or buttocks. You are right, my son is an adult and he wears the sensor on the abdomen.What I find confusing is that this guidance refers to children but, in you first post, you said 'My son was diagnosed T1D about 20 months ago, aged 24'. Is this a mistake?