Single parents are not allowed to enlist in the active-duty military. Except for the Reserve components of the military and Army National Guard, waiver approvals are rare, and most recruiters won't even submit one. Prior to the 2000s, some recruits would try to get around this restriction by giving up legal custody of their child(ren) until after basic training and job school, then regain custody.
If they did not have a solid Family Care Plan when stationed at their first duty station, it would be evident to the chain of command as it causes major problems for everyone. The military has since banned this practice. As a result of wartime deployments in the early 1990s, the Department of Defense (DOD) published DOD Instruction 1342.19, Family Care Plans, to standardize the requirements for all of the military services.
Enlistment for Single Parents Isn't Possible Without Custody Transfer
Additionally, the military services stopped accepting single-parents for enlistment in the military because they saw the problems that long-term combat deployments caused. After the attacks on September 11, 2001, with more than 15 years of sustained combat action, the chances for single parents joining is impossible without custody transfer.
And, if already in active duty and you become a single parent, you have to have a Family Care Plan that guarantees someone local (nonmilitary) is basically on call (in writing) 24 hours a day 7 days a week to take care of your child in case you cannot. Failure to comply with these "Family Care Plans" can (and does) result in an immediate discharge.
Joining the military with a child and no family care plan can lead to difficulty for the military member, child, and the chain of command. The long hours at work, periods of travel, and long deployments are not conducive to a single-parent family. Someone has to be responsible for taking care of the children at all times. If it is not the parent, it has to be given to a trusted member of the family (typically) by court order.
Single Parents in the Marine Corps and Navy
In the Marine Corps, one must give up legal custody (by court order) of their child(ren), and then wait one year or more before being eligible for enlistment. For Navy enlistments, the waiting period is six months and the court order must make it very plain that the transfer of custody is permanent. Typically, custody given to grandparents of the dependent child is an acceptable option.
Single Parents in the Army and Air Force
In the Army and Air Force, single-parent military applicants for enlistment must indicate they have a child or children in the custody of the other parent or another adult. They are then advised and required to acknowledge by a certification that their intent at the time of enlistment was not to enter the Air Force or Army with the express intention of regaining custody after enlistment.
These applicants must execute a signed statement testifying they have been advised that, if they regain custody during their term of enlistment, they will be in violation of the stated intent of their enlistment contract. They may be subject to involuntary separation for fraudulent entry unless they can show cause, such as the death or incapacity of the other parent or custodian, or their marital status changes from single to married.
The military's refusal to accept single parents for enlistment is a valid one. The military is no place for a single parent. In the military, the mission always comes first. Absolutely no exceptions are made in assignments, deployments, duty hours, time off, or any other factor for single parents.
In general, an applicant who has joint physical custody of a child by court order or agreement, and the applicant does not have a spouse, he/she is considered a "single parent." If a local or state court allows modification, if the other parent assumes full custody, the applicant is usually qualified for enlistment.
In the Army National Guard, a single parent may enlist if they receive a waiver from the State Adjutant General of the state that an individual is enlisting.