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What Is the Net Investment Income Tax?

SmartAsset: What Is the Net Investment Income Tax?

Investing has the potential to earn you great returns – but where money’s being made, you can surely find Uncle Sam nearby. Accordingly, the net investment income tax (NIIT) will take a 3.8% bite out of a portion of your investment earnings. There are, however, a number of restrictions on what the NIIT does and doesn’t apply to. Take a look through our detailed guide below for more insight.

For more help with tax planning, consider working with a financial advisor. You can match with up to three who serve your area by trying SmartAsset’s free advisor matching tool.

All About the Net Investment Income Tax

The net investment income tax, or NIIT, is an IRS tax related to the net investment income of certain individuals, estates and trusts. More specifically, this applies to the lesser of your net investment income or the amount by which your modified adjusted gross income (MAGI) surpasses the filing status-based thresholds the IRS imposes. The NIIT is set at 3.8% for 2024, as it was for 2023.

To give some background, the net investment income tax is part of the Health Care and Education Reconciliation Act of 2010. While the NIIT might seem out of place here, it was actually created to help fund the aforementioned healthcare reforms. Ultimately, the law went into effect in 2013, giving birth to the NIIT on Jan. 1 of that year. Since then, millions of Americans have paid the tax.

Who’s Subject to the Net Investment Income Tax?

Individuals are frequent net investment income taxpayers, mostly because they represent a large portion of the investment market. Only U.S. citizens and resident aliens with net investment income that exceeds the MAGI thresholds in the table below need to pay the NIIT, though. On the other hand, non-resident aliens are not subject to this tax. The only exception is if they elect to be treated as a resident so they can file jointly with their U.S. citizen or resident spouse. Check out the exact thresholds here:

Net Investment Income Tax (NIIT) Thresholds

Your Filing StatusThreshold Amount
Married Filing Jointly$250,000
Married Filing Separately$125,000
Head of Household (With Qualifying Person)$200,000
Qualifying Widow(er) With Dependent Child$250,000

Estates and trusts may also need to pay the NIIT. This pertains to estates and trusts that have both undistributed net investment income and adjusted gross income past the dollar amount at which the highest estate/trust tax bracket begins for the current tax year. For 2024, this amount is $15,200, which is up from $14,450 in 2023.

The IRS stipulates that there are a few types of trusts not subject to the NIIT, including:

  • Trusts that are exempt from income taxes
  • Grantor trusts
  • Trusts not technically classified as “trusts” for federal income tax purposes
  • Perpetual care trusts
  • Electing Alaska Native Settlement Trusts

What Is Net Investment Income?

SmartAsset: What Is the Net Investment Income Tax?

In order to turn a profit, investors aim to buy investments at a lower price than they’ll eventually sell them for. But there are many different kinds of investments, and not all of them are included as net investment income. Here’s a rundown of what is and isn’t subject to the NIIT:

Net Investment Income (NII) Inclusions and Exclusions

Included as NII– Interest
– Capital gains
– Dividends
– Income from passive investment activities
– Non-qualified annuity distributions
– Rental and royalty income
Excluded from NII– Wages
– Unemployment payments
– Self-employment income
Social Security benefits
– Distributions from some qualified retirement plans
– Alimony
– Tax-exempt interest
– Operating income from non-passive businesses
– Excluded capital gains earned from the sale of your primary residence
– Alaska Permanent Fund Dividends

The Net Investment Income Tax in Practice

Your modified adjusted gross income (MAGI) determines if you owe the net investment income tax. You can compute your MAGI by taking your adjusted gross income (AGI) and adding back in a few deductions, like IRA contributions, passive loss or income, taxable Social Security payments, student loan interest and more. You can find your AGI on Form 1040, Line 8b. If your MAGI is higher than the statutory threshold for your filing status, then you must pay the net investment income tax.

Next, you’ll need to figure out your net investment income based on the included earnings listed above. But before you can calculate your NII, you must know your gross investment income. Once you have that, subtracting eligible deductions from your gross investment income will provide you your NII. Some common investment deductions are brokerage fees, investment advisory fees, tax preparation charges, local and state income taxes, fiduciary expenses, investment interest expenses and any costs involved with rental and royalty income.

Earlier we stated that you pay the NIIT based on the lesser of your net investment income or the amount by which your modified adjusted gross income (MAGI) surpasses the filing status-based thresholds imposed by the IRS. In simpler terms, the dollar amount that’s subject to this 3.8% tax, will vary as follows:

  • If your net investment income is lower than the amount by which you exceeded the statutory threshold, the tax applies to your NII.
  • If your net investment income is higher than the amount by which you exceeded the statutory threshold, the tax applies to that exceeding value.

Here are a few examples of NIIT:

Examples of Net Investment Income Tax

Filing StatusMAGI Statutory ThresholdYour IncomeAmount Subject to the NIITTaxes Owed
Single$200K$120K (wages) + $40K (NII) = $160K (MAGI)$0$0
Single$200K$170K (wages) + $80K (NII) = $250K (MAGI)$50K$1,900
Married Filing Jointly$250K$220K (wages) + $45K (NII) = $265K (MAGI)$15K$570
Married Filing Separately$125K$150K (wages) + $40K (NII) = $190K (MAGI)$40K$1,520

How to File the NIIT

SmartAsset: What Is the Net Investment Income Tax?

IRS Form 8960 is devoted to the calculation of the net investment income tax. When you’re ready to report and pay your NIIT, you’ll do so via Form 1040. Estates and trusts looking to file the NIIT should use Form 1041. If you come across issues or specific questions related to this tax, you may want to consult a financial advisor or a certified public accountant (CPA).

According to the IRS, if you believe that you will pay the NIIT for the current tax year, you must account for it ahead of time. This involves either adjusting your income tax withholding or setting up quarterly estimated payments. Although this requires extra work, it could save you from underpaying the IRS come tax time.

Tips for Managing Your Investments

  • Taking care of your investments can sometimes fall by the wayside, but this is extremely detrimental over the long-term. A financial advisor can help keep your finances on track. Finding a financial advisor doesn’t have to be hard. SmartAsset’s free tool matches you with up to three vetted financial advisors who serve your area, and you can have free introductory calls with your advisor matches to decide which one you feel is right for you. If you’re ready to find an advisor who can help you achieve your financial goals, get started now.
  • In order to accurately plan your financial future, you should calculate what kind of returns you’ll need from an investment portfolio to reach your goals. There are a few ways to do this, including SmartAsset’s investment calculator or the rule of 72.

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