Due mostly to financial illiteracy, too many doctors actually think half of their money goes to taxes. Sometimes that's just because, as employees, they lump everything coming out of their paycheck (taxes, retirement account contributions, health insurance) into the term “taxes.” Sometimes it's because they're having WAY TOO MUCH money withheld from their paychecks and get massive tax refunds every year. But most commonly, it's simply because they don't understand the difference between marginal and effective tax rates. Let's talk about the differences today. What Is a Marginal Tax Rate? Your marginal tax rate is the percentage of the next dollar you earn that goes to taxes. If you earn one more dollar and 45 cents of it goes to taxes, your marginal tax rate is 45%. While it's not exactly the same due to phaseouts and other quirks in the tax code, you can think of this as your tax bracket . This tax rate can be very high.…