Yes. There are modifications to playing rules up until U16s. Some of these changes might include, smaller basketballs, lower rings, reduced enforcement of violations (such as travel/double dribble/cross court/seconds in the key), free throw shots from closer to the ring, and a mercy rule.
These rules are constantly being monitored by the SPBA and regularly discussed with clubs. Up to date information can be found in the domestic competition rules (by laws) available on the SPBA website.