The frontline of the health systemcomprises the primary health care (PHC) system, the networksof frontline health workers, and other public- orprivate-sector services or institutions that serve asfirst-touch points with the public health and health caresystems, as well as channels outside the formal health careinfrastructure that help communities, households, andindividual co-produce positive health outcomes.Thesefrontline networks represent the first point of contactbetween individuals and the health system: they are thebackbones of effective health systems, best positioned tooffer first-level assessment, treatment, and healtheducation. Functional frontline networks also connectfamilies and communities to critical care and the broaderhealth system; they operate most effectively as anintegrated part of a multilayered PHC team, requiring afunctional two-way referral system between frontlines andfirst-level referral facilities.