The year 2019 has just begun, and it's almost time for taxpayers to start thinking about preparing their returns for the past year. Yet even as you focus on what happened in the 2018 tax year, you're already going to see the impact of the minor changes to the 2019 tax brackets that took effect at the beginning of this year.

The changes to the IRS brackets for 2019 weren't nearly as complex as they were last year, because tax reform fully took effect in 2018. That means that this year, the only changes you'll see from the 2018 tax brackets have to do with the annual adjustments for inflation that get made to the numbers. Absent further changes to the tax laws, taxpayers can expect to get quite familiar with the basic structure of these brackets for years to come -- at least until their scheduled sunset after the 2025 tax year.

Alarm clock, piles of coins, and letter magnets spelling tax on a wood table in front of a pale blue-green wall.

Image source: Getty Images.

2019 tax brackets for singles

Those who aren't married and don't qualify as a head of household or a surviving spouse pay taxes according to the following brackets:

Bracket

Tax is this amount plus this percentage...

...Of the amount over

$0 to $9,700

$0 plus 10%

$0

$9,700 to $39,475

$970 plus 12%

$9,700

$39,475 to $84,200

$4,543 plus 22%

$39,475

$84,200 to $160,725

$14,382.50 plus 24%

$84,200

$160,725 to $204,100

$32,748.50 plus 32%

$160,725

$204,100 to $510,300

$46,628.50 plus 35%

$204,100

Above $510,300

$153,798.50 plus 37%

$510,300

Data source: IRS.

2019 tax brackets for heads of household

If you qualify as a head of household, then you enjoy larger tax brackets that give you more benefit from low tax rates than most single filers. In general, in order to be considered a head of household, you need to be unmarried and provide a home and financial support for a child, parent, or other relative who lives with you more than half the year. Qualifying relatives must generally be considered dependents, although now that the new tax laws have taken away dependent exemptions as a reduction to taxable income, the standards won't be as obvious as they've been in past years.

Bracket

Tax is this amount plus this percentage...

...Of the amount over

$0 to $13,850

$0 plus 10%

$0

$13,850 to $52,850

$1,385 plus 12%

$13,850

$52,850 to $84,200

$6,065 plus 22%

$52,850

$84,200 to $160,700

$12,962 plus 24%

$84,200

$160,700 to $204,100

$31,322 plus 32%

$160,700

$204,100 to $510,300

$45,210 plus 35%

$204,100

Above $510,300

$152,380 plus 37%

$510,300

Data source: IRS.

2019 tax brackets for married joint filers

If you're married, the following tax brackets apply as long as you file jointly. Surviving spouses are also allowed to use these brackets for a period of time after the death of the spouse.

Bracket

Tax is this amount plus this percentage...

...Of the amount over

$0 to $19,400

$0 plus 10%

$0

$19,400 to $78,950

$1,940 plus 12%

$19,400

$78,950 to $168,400

$9,086 plus 22%

$78,950

$168,400 to $321,450

$28,765 plus 24%

$168,400

$321,450 to $408,200

$65,497 plus 32%

$321,450

$408,200 to $612,350

$93,257 plus 35%

$408,200

Above $612,350

$164,709.50 plus 37%

$612,350

Data source: IRS.

2019 tax brackets for married separate filers

Married taxpayers who elect to file separate returns have to use different brackets. The amounts are basically half of what you see in the brackets for married taxpayers filing jointly.

Bracket

Tax is this amount plus this percentage...

...Of the amount over

$0 to $9,700

$0 plus 10%

$0

$9,700 to $39,475

$970 plus 12%

$9,700

$39,475 to $84,200

$4,543 plus 22%

$39,475

$84,200 to $160,725

$14,382.50 plus 24%

$84,200

$160,725 to $204,100

$32,748.50 plus 32%

$160,725

$204,100 to $306,175

$46,628.50 plus 35%

$204,100

Above $306,175

$82,354.75 plus 37%

$306,175

Data source: IRS.

2019 tax brackets for trusts and estates

Lastly, trusts that are taxed as separate entities have their own tax brackets, as do estates of deceased taxpayers. These brackets are also relevant for taxpayers whose children have enough unearned income to trigger what's known as the kiddie tax.

Bracket

Tax is this amount plus this percentage...

...Of the amount over

$0 to $2,600

$0 plus 10%

$0

$2,600 to $9,300

$260 plus 24%

$2,600

$9,300 to $12,750

$1,868 plus 35%

$9,300

Above $12,750

$3,075.50 plus 37%

$12,750

Data source: IRS.

Don't panic about your bracket

Lastly, there's one common mistake that most people make in looking at tax brackets. Just because your income moves you up from one bracket to the next doesn't mean that all of your income gets taxed at the new higher rate. For instance, say you're a head of household and have taxable income of $52,850. Using the appropriate chart above, you'll see that your taxes are $6,065, working out to an effective rate of about 11.5%. That makes sense, since you're at the top of the 12% tax bracket.

However, if your income climbed by $100 to $52,950, many fear that by being in the 22% tax bracket, you'd see a huge tax increase. But if you run the numbers again, you'll see that your tax would now be $6,087 -- or $22 higher. That makes sense, because the 22% rate applies only to that extra $100 you brought in. Your effective tax rate would still be 11.5%.

In the coming months, taxpayers will pay most of their attention to getting their 2018 tax returns prepared. But knowing the 2019 tax brackets will help you plan for tax filing when next year rolls around.

The Motley Fool has a disclosure policy.