Background: In the Netherlands, Flexible Assertive Community Treatment (FACT) teams have been established for people with mild intellectual disability (MID) or borderline intellectual functioning (BIF) and mental health problems or challenging behaviour. Little is known yet about service users' experiences with FACT. Method: An inductive grounded theory approach was used to explore how service users valued the treatment and their own functioning, and which factors were perceived as supportive. Semi-structured interviews were held with 15 service users. Results: Most service users highly appreciated the contact with the staff and the practical and emotional support. Persistent involvement, availability and humanity, and respect for autonomy were distinguished as core values in the relationship with the staff. Most service users experienced improvement in time and attributed this to intrapersonal changes and/or less stress in life. Conclusions: From the perspective of service users with MID/BIF, FACT appears to have an added value.