The addition of new members is decided by a majority vote of the existing membership. Rarely, someone might be granted membership on a probationary basis prior to a confirmatory vote. A member can also be ejected by majority vote if they are felt not to uphold the League's standards.
It has become a generally accepted norm that only legal adults are considered for League membership, and that minors who cannot be persuaded away from superheroics are best served by joining the Team. There is one notable exception to this rule.
The League offers a stipend to its members, as well as members of the Team.
Leadership is determined by regular elections. Chairpersons typically serve one-year terms, and usually do not seek more than two terms in a row.All other members are considered equals. Batman was the leader in 2010. In late 2015, Captain Atom became the leader, until July 4, 2016, when Black Canary took over. By 2018, the leaders were Kaldur'ahm, the second Aquaman, and Wonder Woman, acting as co-chairs and representatives for the League on Earth and in space, respectively. On February 24, 2019, Black Lightning was elected to leadership,and later re-elected for a second consecutive term.
Following the global crisis wrought by Child in May 2020, Superman suggested setting up an official reserve system for large scale emergencies. A recruitment committee was set-up by July of that year. Among the many individuals considered were former League and Team members, Atlanteans allied to Aquaman, and Zatanna's magicalprotégés and friends, as well as other heroes known to the League.
The League is permitted to operate by means of a U.N. Charter. League members have no jurisdiction within the borders of nations that have not signed the U.N. Charter, such as Bialya,Markovia Russia and Santa Prisca. During Lex Luthor's tenure as U.N. Secretary General, the League's diplomatic reach was curtailed considerably.
The League also has a relationship with the U.S. government, and is considered by some to be an American organization.
The League gets some of its funding from the United Nations, as well as private donations. The Wayne Foundation is a major donor.
After Green Arrow and Black Canary encountered Amazo in rural Connecticut, half the League, including the powerhouses Superman and Captain Atom, responded. Their presence nearly proved disastrous as Amazo was able to copy all their powers. Eventually, the android was dismantled.
With the Injustice League's plant creatures sprouting up all over the world, Batman made sure the entire Justice League fought them to draw attention away from the Team as they went for the Injustice League's headquarters in the Louisiana bayou. They eventually made their way there too to force them to surrender.
After the incident on Rimbor with six mind-controlled Leaguers, the entire Justice League was declared unwelcome in the sector surrounding Rann. Not having figured out what happened during the sixteen hours unaccounted for during their enslavement, the Justice League was initially unaware of this ban.
The League and the Team discussed an alien attack on the UN. From Adam Strange, they learned Kroloteans were behind Zeta-Beam thefts on Rann, and that the Leaguers were unwelcome there—six were even wanted criminals. The Team sent a squad to Rann, while the League and the Team set up strike groups to target Kroloteans on Earth.
After Mal Duncan alerted everyone that the main Krolotean hideout was found by Gamma Squad, all twenty-one active members of the League rushed to New Orleans. When they arrived, they saw Robin, Blue Beetle and Lagoon Boy had already freed the hostages, and the base was destroyed.
After Miss Martian discovered what the League had done in the missing sixteen hours, Captain Atom and John Stewart discussed what to do. John convened with the Guardians of the Universe, and they thought it best that the six Leaguers traveled to Rimbor to defend themselves. Hawkman accompanied his spouse, and Icon joined because he had experience with intergalactic tribunal law.
The general populace was not made aware that eight powerful members of the League were off-planet. The League and the Team set up a ruse, and Miss Martian and Superboy at times impersonated Martian Manhunter and Superman to keep up the impression that they were still at full strength.
The Hall of Justice was invaded by the alien gladiator Despero, who sought to best Earth's mightiest champions in single combat. Though the warrior was eventually defeated, the Hall was destroyed in the process. When the Reachambassador arrived to "help" by removing the force field Despero had placed around the Hall, he casually let slip the existence of the Watchtower before the news cameras.
Superman testified before the High Court of Rimbor, explaining, not for the first time, how the League was compelled to attack the planet. The trial remained ongoing as the League refused to bribe their way to freedom.
While most of the League continued to deal with the problems the Warworld created on Earth, Captain Atom, Captain Marvel, Doctor Fate and Rocket defended Earth from Mongul's attacks and launched a counter-assault on the Warworld's surface. Meanwhile, the Team infiltrated the satellite and disbaled it.
After Miss Martian, Superboy and Adam Strange presented new evidence—a video recording of the Light admitting their subjugation of the League—and convinced the Tribune of the future profitability of a fair verdict in the case, the accused Leaguers were found innocent and released.
A group of forty heroes, including all the Leaguers on Earth, gathered for a briefing on the plan to stop the Magnetic Field Disruptors planted by the Reach to destroy Earth. The heroes paired off and attacked the MFDs simultaneously. Within thirty minutes, the twenty MFDs were disabled.
Captain Atom turned over chairmanship of the League to Black Canary. Later, Batman, Canary and the Team's mentors gathered to tell the Team that they would now operate from the Watchtower beside the League.
Batman and Nightwing set up an all-hands meeting for the League, The Team, the Outsiders and their own operatives. They came clean about their secret involvement in the Outsiders; they had orchestrated most of their successes to create a team that could better the public image of heroes and combat the Light in ways the League and Team couldn't.
For their complicity in the plot, Aquaman and Wonder Woman stepped down as leaders, as did Miss Martian for the Team. The recently rejoined Black Lightning, who had proven himself a moral compass in recent months, was unanimously elected new leader. Under his terms, the League would no longer scheme in the shadows, and Batman and his operatives folded back into the League and Team.
After dealing with the blizzard and pillar of fire created by Child, Superman suggested to Black Lightning that they needed to create an official reserve system to deal with such major crises.
On July 3, Orin decided to return to the League as Aquaman. He suggested La'gaan also join as a third Aquaman. Kaldur'ahm began a leave of absence at this time, which lasted approximately one month. The new and returning Aquamen were later accepted.
Each member of the Justice League has a membership number, which is read out when they enter restricted areas of the Hall of Justice.With the exception of the seven founders, who have designations 01 to 07, these designations indicate the order of the members' induction into the League.For the founders, their designations indicate the order in which they had arrived to battle the Appellaxians, before the League was formed.