Answer:
There is no phase out limit for contributions to Section 529 plans. The limit on how much money you can contribute to a plan is $15,000 per year, but it doesn't phase out if you have a high income.
The main differences between a Coverdell account and a 529 account is that the Coverdell account has an age limit of 30, an income limit of $220,000 and a maximum annual contribution of $2,000.