The FIG imposes a minimum age limit on gymnasts competing in international meets. The term senior, in gymnastics, refers to any world-class/elite gymnast who is age-eligible under FIG rules.

Currently, gymnasts must be at least sixteen years of age, or turning sixteen within the calendar year to compete in senior-level events. The one exception to this rule is the year before the Olympics, when gymnasts who are one year shy of the age requirement may compete at the Worlds and other meets. For instance, gymnasts born in 1988 were allowed to compete in senior events in 2003. This is permitted to allow nations to qualify to the Olympics with their best teams, and to give emerging gymnasts some experience in major competition before the Olympics.

The term junior refers to any gymnast who competes at a world-class/elite level, but is too young to be classified as a senior. Juniors are judged under the same Code of Points as the seniors, and often exhibit the same level of difficulty in their routines.

Only senior gymnasts are allowed to compete in the Olympics, World Championships and World Cup. However, many meets, such as the European Championships and Pacific Alliance, have separate divisions for juniors. Additionally, some competitions, such as the Goodwill Games, the Pam Am Games and the All-Africa Games, have rules that permit seniors and juniors to compete together.

The minimum age requirement is arguably one of the most contentious rules in artistic gymnastics, and is frequently debated by coaches, gymnasts and other members of the gymnastics community. Those in favor of the age limits argue that they promote the participation of older athletes in the sport, and that they spare younger gymnasts from the stress of competition and training at a high level. Opponents of the rule point out that junior gynnasts are scored under the exact same Code of Points as the seniors, and train, mostly, the same skills. They also feel that younger gymnasts need the experience of participating in major meets in order to become better athletes; and that if a junior has the skills and maturity to be competitive with seniors, he or she should be allowed that opportunity.

Another point that frequently arises in this debate is the issue of age falsification. Since stricter age limit rules were first adopted in the early 1980s, there have been several well-documented, and many more suspected, cases of juniors with falsified documents competing as seniors. In only one case — that of Kim Gwang Suk of North Korea, who competed at the 1989 World Artistic Gymnastics Championships at the approximate age of eleven — has the FIG taken any disciplinary action.

While the minimum age requirement applies to both WAG and MAG, it is far more contentious in WAG. Most top male gymnasts are in their late teens or early twenties; female gymnasts are typically ready to compete at the international level by their mid-teens.