Your goal as a taxpayer should be to pay the IRS as little money as possible. And thankfully, there are a host of tax breaks that allow you to achieve that goal -- legally, of course! Here are a few key opportunities you should know about for both the 2020 and 2021 tax year.

1. The mortgage interest deduction

Being a homeowner has its benefits. If you itemize on your tax return and have a mortgage, you're eligible to deduct the interest you pay on a home loan of up to $750,000. For mortgages that were in place prior to Dec. 15, 2017, that threshold increases to $1 million.

The mortgage interest deduction can be particularly valuable during the early stages of your mortgage-payoff period, when more of your monthly payments go toward your loan's interest than its principal.

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2. The SALT deduction

The state and local tax deduction, or SALT deduction, is worth up to $10,000. That's a large write-off if you itemize and pay enough state income and property taxes to reach that threshold. In a number of high property tax states, like New Jersey, that's a pretty easy limit to hit.

3. The Earned Income Tax Credit

The Earned Income Tax Credit, or EITC, is a tax credit designed for low-income households. What makes the EITC so valuable is that it's one of the few credits that's actually fully refundable, so if it reduces your tax liability to below zero, the IRS will pay you the difference.

EITC eligibility depends on your income and the number of qualifying children you have in your household. Its maximum value also changes from year to year. In 2020, the EITC is worth up to $6,660. In 2021, it's worth up to $6,728.

4. The Child Tax Credit

What makes the Child Tax Credit so great is that it's fairly easy to qualify for. Whereas many tax credits begin to phase out at lower income levels, you can be a high earner and still capitalize on the Child Tax Credit in full.

In both 2020 and 2021, the Child Tax Credit is worth up to $2,000 per child in your household under the age of 17. And of that $2,000, up to $1,400 is refundable, so if the credit knocks your tax liability to less than zero, you'll still get paid something.

The Child Tax Credit begins to phase out for single tax filers earning $200,000 and married couples filing jointly earning $400,000. Beyond that point, you'll lose $50 per $1,000 you earn. But clearly, that still makes the credit accessible to most U.S. filers with kids.

5. Traditional retirement plan contributions

If you put money into a Roth IRA or 401(k) plan, you won't get an immediate tax break (though there are still benefits to saving in one of these accounts). But if you fund a traditional IRA or 401(k) plan, your contribution will exempt a portion of your income from taxes.

For both 2020 and 2021, IRA contributions max out at $6,000 for workers under 50 and $7,000 for those 50 and older. For 401(k)s, the limits for both 2020 and 2021 are $19,500 for workers under 50 and $26,000 for those 50 and older. What this means is if you put $6,000 into an IRA, you won't be taxed on $6,000 of your earnings. If you're in the 22% tax bracket, that means you'll reap $1,320 of tax savings.

6. HSA contributions

Like traditional IRA and 401(k) contributions, health savings account (HSA) contributions are also tax-free. To qualify to participate in an HSA, you must be enrolled in a high-deductible health insurance plan. For both 2020 and 2021, that means having an individual deductible of at least $1,400 or a family level deductible of at least $2,800.

From there, 2020's HSA limits are $3,550 if you're saving as an individual and $7,100 if you're saving on behalf of a family. In 2021, these limits are rising to $3,600 and $7,200, respectively. And like IRAs, HSAs offer older savers a $1,000 catch-up on top of these limits. The only difference is that IRA catch-ups begin at age 50, whereas with HSAs, they begin at age 55.

Paying taxes may be a drag, but the good news is that there are plenty of opportunities to lower that burden substantially. It pays to read up on the ways you can shrink your tax bill and keep more of your hard-earned money for yourself.