Host Nation Support (HNS) is important for both Sweden and NATO's joint strategy on deterrence, but is a new phenomenon. This study aims to increase knowledge about the understanding and implementation of HNS in Sweden. The material in the study consists of interviews with people who work with HNS in Sweden. Snowball sampling was used to select organizations and informants since strategic selection was not possible. A thematic analysis was then carried out to analyze the material. This resulted in four themes that concern knowledge creation, planning, NATO and legal obstacles. The conclusion was that host nation support in Sweden is a living, dynamic and largely practice-oriented capability where international requirements, flexibility and legal constraints coexist.