You thought you had learned everything you needed to know about taxes and finance, but now that you’re retiring, you find out there is a whole new set of rules to learn. Here are the five most important things you should know about taxes after retirement.

1. You must pay taxes on retirement accounts funded by pre-tax income:

This means that the money you withdraw from accounts that you contributed tax-deferred income to, such as IRAs

, 401(k)s

, annuities and many pensions, is now subject to federal income tax. The benefit of those accounts was being able to earn interest on that money or invest it in stocks and bonds before paying income tax, but now the IRS wants its share.

2. Capital gains taxes:

If you’ve held onto long-term investments

but are now cashing in some of them for living expenses during retirement, you’ll now be liable for capital gains taxes. The good news is that long-term capital gains (those investments held for more than a year) are taxed at a low rate. Most people will pay 15 percent, while those in the lowest income brackets will pay zero percent, and those in the highest owe 20 percent.

3. You might lose some tax deductions: 

Most of the itemized deductions that many people are able to take, especially small business owners and independent contractors, won’t be available when you retire (unless you continue to work part-time or oversee a business). Retirees often have a lower income after they retire, and that can mean being in a lower tax bracket where taking the standard deduction instead of itemized deductions is often the best option.

4. Tax from sale of home:

Many retirees sell their home

and move into a smaller house or condo, both because their children are now adults and because it can help generate more income since they are no longer working. For those who have paid off their mortgage, or at least accrued a large amount of equity, this can mean facing a big tax bill. The good news is that profit from sale of a home is only taxed after the first $500,000 for a married couple and $250,000 for an individual.

5. Paying taxes on Social Security:

If your only income during retirement comes from Social Security, then you won’t owe taxes on it. However, depending on the amount of other sources of income, you could be required to consider part of your SS payments as taxable income. Individuals with a “combined income” (adjusted gross income plus non taxable interest plus 50 percent of their SS benefits) between $25,000 and $34,000 (or spouses who file jointly with income between $32,000 and $44,000) must pay income tax on half of their Social Security benefits. Those with incomes of more than $34,000 ($44,000 for joint returns) are responsible for income taxes on 85 percent of their SS benefits.