The US has no minimum requirements to meet before you are allowed to move up. You may start at any level you like, and you may move on to any level you like when you, your partner, and your coach feel you're ready for it.
That's not to say that there is no point system in the US, because there is. The point system in the US is designed to keep advanced dancers out of lower levels, rather than being designed to keep lower level dancers out of higher level events.
In the US, you win a point if:
* You win a competition at your current level that had a semi-final.
OR
* You come in 1-3 in a competition (with a semi-final) at a higher level than your current one.
OR
* You make the final in a competition (that started in a quarter-final) at a higher level than your current one.
When you've earned three points, you are no longer eligible to dance at your current level. As an example, a person starting at the bottom of syllabus might dance in Bronze and some Silver events. When they earn three points, they will not be eligible to dance in Bronze any more.