The Order of the Arrow has more than 160,000 active members located in lodges affiliated with over 270 BSA local councils. As of August 2018, there is now an OA lodge in every council across the United States
Beginning February 1, 2019, unit elections will be permitted in Scouts BSA, Venturing, and Sea Scout units. The new Order of the Arrow membership requirements are as follows:
- Be a registered member of the Boy Scouts of America.
- Have experienced 15 nights of camping while registered with a troop, crew, or ship within the two years immediately prior to the election. The 15 nights must include one, but no more than one, long-term camp consisting of at least five consecutive nights of overnight camping, approved and under the auspices and standards of the Boy Scouts of America. Only five nights of the long-term camp may be credited toward the 15-night camping requirement; the balance of the camping (10 nights) must be overnight, weekend, or other short-term camps of, at most, three nights each. Ship nights may be counted as camping for Sea Scouts.
- At the time of their election, youth must be under the age of 21, hold the Scouts BSA First Class rank, the Venturing Discovery Award, or the Sea Scout Ordinary rank or higher, and following approval by the Scoutmaster, Crew Advisor or Sea Scout Skipper, be elected by the youth members of their unit.
- Adults (age 21 or older) who meet the camping requirements may be selected following nomination to and approval by the lodge adult selection committee.
While there are three levels of membership (called "honors") in the Order of the Arrow, all members—regardless of honor—are considered equal.
The induction ceremony, called the Ordeal, is the first step toward full membership in the Order. During the experience, candidates maintain silence, receive small amounts of food, work on camp improvement projects, and sleep apart from other campers. The entire experience is designed to teach significant values. All candidates for membership must complete the Ordeal.
After 10 months of service as an Ordeal member and fulfilling certain requirements, a member may take part in the Brotherhood ceremony, which places further emphasis on the ideals of Scouting and the Order. Completion of this ceremony signifies full membership in the Order.
After two years of exceptional service as a Brotherhood member, and with the approval of the national Order of the Arrow committee, a Scout or Scouter may be recognized with the Vigil Honor for their distinguished contributions to their lodge, the Order of the Arrow, Scouting, or their Scout camp. This honor is bestowed by special selection and is limited to one person for every 50 members registered with the lodge each year.