I didn't write this but it's a cut and paste job from the MLB site:
A club that exceeds the Competitive Balance Tax threshold is subject to an increasing tax rate depending on how many consecutive years it has done so.
First year: 20 percent tax on all overages
Second consecutive year: 30 percent
Third consecutive year or more: 50 percent
There’s also a surcharge threshold for clubs that exceed the base threshold by $20 million or more.
$20 million to $40 million: 12 percent surcharge
$40 million to $60 million: 42.5 percent surcharge for first year; 45 percent for each consecutive year after that
$60 million or more: 60 percent surcharge
A club that exceeds the Competitive Balance Tax threshold is subject to an increasing tax rate depending on how many consecutive years it has done so.
First year: 20 percent tax on all overages
Second consecutive year: 30 percent
Third consecutive year or more: 50 percent
There’s also a surcharge threshold for clubs that exceed the base threshold by $20 million or more.
$20 million to $40 million: 12 percent surcharge
$40 million to $60 million: 42.5 percent surcharge for first year; 45 percent for each consecutive year after that
$60 million or more: 60 percent surcharge