Unmanned Aircraft Systems (UASs) have advanced technologically and surged expo-nentially over recent years. Currently, due to safety concerns, most civil operations of UAS are con-ducted in low-level uncontrolled area or in segregated controlled airspace. As the industry progresses, both operational and technological capabilities have matured to the point where UASs are expected to gain greater freedom of access to both controlled and uncontrolled airspace. Exten-sive technical and regulatory surveys have been conducted to enable the expanded operations. How-ever, most surveys are derived from the perspective of UAS own operating mechanism and barely consider interactions of their non-segregated activities with the Air Traffic Management (ATM) sys-tem. Hence, to fill the gap, this paper presents a survey conducted from the perspective of Air Nav-igation Service Provider (ANSP), which serves to accommodate these new entrants to the overall national airspace while continuing flight safety and efficiency. The primary objectives of this paper are to:(A) describe what typical ANSP-supplied UAS Traffic Management (UTM) architecture is required to facilitate all types of civil UAS operations; (B) identify three major ANSP considera-tions on how UAS can be accommodated safely in civil airspace; (C) outline future directions and challenges related with UAS operations for the ANSP.