Enhancing America's Core Diplomatic Capabilities Act of 2019 This bill revises various provisions related to Foreign Service staffing and training, including by setting minimum staffing requirements. The Department of State shall take all practicable measures to maintain within the service certain staffing levels at various experience levels, including at least 905 senior officers. The State Department shall (1) periodically report to Congress on service staffing levels, (2) explain reasons for any failure to meet minimum targets, and (3) provide a plan to address any deficiencies. The State Department shall appoint a Director of Human Resources. The bill revises the qualifications for certain director positions within the service. The State Department shall reestablish the Senior Seminar in Foreign Policy, which shall select participants based on past performance and future potential. The State Department may (1) suspend maximum in-class limits for a member of the service while the member is engaged in long-term training, and (2) establish an incentive program to encourage members of the service to maintain skills in critical foreign languages. The State Department's entry-level appointments for the service shall be based on (1) long-term projections designed to provide for the regular and predictable recruitment and promotion of staff, and (2) career development patterns designed to meet the service's needs.