Source: Pixabay.

The estate tax is one of the most complex parts of the tax laws, drawing a lot of controversy among Americans. Even as opponents label it an unfair death tax on already-taxed money, proponents believe it's one of the only ways of addressing rising inequality in wealth levels within the nation. Still, with the government collecting almost $12.7 billion from estate tax filings last year, it's worth your while to know enough about how estate tax rules change from year to year that you can avoid or minimize any tax you might owe. With that in mind, here are five rules you need to know about the estate tax for 2015.

1. Estate tax exclusion amount goes up to $5.43 million.

The federal estate tax applies only to those whose taxable estates exceed a certain amount. The estate tax exemption was set to $5 million in 2011, and each year after that, the exemption amount has risen at the rate of inflation. For 2015, the exemption will go up $90,000 from 2014's $5.34 million amount, giving everyone a $5.43 million estate tax exemption.

One thing to keep in mind is that the U.S. has a unified gift and estate tax system, which means that taxable gifts count against your estate tax exemption. So if you make taxable gifts during your lifetime, you'll effectively use up some of this $5.43 million in advance -- but the upside is that you won't have had to pay gift tax at the time you made the gift.

2. Annual gift tax exclusions remain at $14,000.

The reason most people never have to file a gift tax return is that there's an annual exclusion that makes most gifts nontaxable. You can give up to $14,000 in cash or property to anyone in 2015, which is the same amount as in 2014. The annual gift tax exclusion is indexed to inflation, but the rate of inflation was small enough this year that the amount, which is rounded down to the nearest $1,000 increment, didn't change.


Source: Flickr, via Wikimedia Commons.

3. With some gifts, you don't have to worry about gift or estate tax.

The estate tax laws have carved out certain types of gifts and bequests that aren't subject to tax. The most common is the marital deduction, which allows you to give as much as you want to a spouse without any gift or estate tax consequences. Charitable donations also aren't subject to tax, either in estates or as gifts during your lifetime.

In addition, you can make gifts for educational expenses or medical expenses in an unlimited amount without any impact on estate or gift taxes. Keep in mind, though, that you need to pay the institution directly, rather than funneling money through the family member or other person who incurred those educational or medical expenses. Otherwise, you won't get the benefit of the exclusion and might have to file a gift tax return.

4. The easy way for married couples to double their estate tax exemptions.

If you're married, the typical estate plan involves leaving everything to your surviving spouse. Yet in the past, doing so raised issues of how to make the most of the deceased spouse's estate tax exclusion. Complicated trust structures were often necessary to make sure both spouses got their full exclusion amount.

Now, though, the deceased spouse's benefits are available later on to the surviving spouse even if they weren't used at the time. That's especially useful for married couples, as it can give the surviving spouse as much as double the total estate tax exclusion. That in turn can save couples as much as $2 million in tax liability. Portability became a permanent part of the estate tax laws at the beginning of 2013, but many people still have out-of-date documents that reflect the old rules. The best planning needs to take this strategy into account in order to take full advantage of it.

The estate tax is a controversial provision, but you still need to make sure you plan for it as well as you can. By keeping these four things in mind, you'll be best prepared t ohandle estate tax issues if they come up in 2015.