In the Active Duty chapters of this report, data are presented for the four DoD Service branches (Army, Navy, Marine Corps, and Air Force). Some information about the DHS’s Active Duty Coast Guard is presented in the Total Military Force chapter of this report. In the Reserve and Guard Members chapter, the label “Total DoD” is used to reflect the six Reserve components under DoD (Army National Guard, Army Reserve, Navy Reserve, Marine Corps Reserve, Air National Guard, and Air Force Reserve), while “Total Selected Reserve” includes DHS’s Coast Guard Reserve data in addition to data from the DoD Reserve components. The data pertaining to Reserve and Guard members depict the Selected Reserve and the National Guard and do not include any other Ready Reserve forces (i.e., Individual Ready Reserve and Inactive National Guard) unless otherwise specified. The introduction to Chapter 3 describes the composition of the Reserve forces of the United States and explains why most data displays are limited to Selected Reserve personnel.