Dentists, doctors, and other business owners can slash their tax bill and funnel huge savings into tax-advantaged retirement vehicles with planning. This is a time-sensitive tax tactic that you might optimally want to implement before the end of this year.

To illustrate how it works, consider a dentist in her peak earnings years, with $500,000 of income. She's married and her children are out of the house. She is in the 35% federal tax bracket, biting deep into her income.

A potent antidote is establishing a federally tax advantaged defined benefit in her practice or joining with her partners in one. Money she salts away into qualified retirement plans is subtracted from her taxable income, reducing her tax bill for this year, and it enables her to manage her tax bracket to optimum advantage.