What is the net investment income tax related to capital gains?

Explore the relationship between net investment income tax and capital gains, and how it affects taxpayers.


The Net Investment Income Tax (NIIT) is a tax that was introduced as part of the Affordable Care Act (ACA) in 2013. It is a 3.8% tax on certain net investment income for individuals, estates, and trusts with income above specific thresholds. The tax primarily affects higher-income taxpayers and is imposed on top of other federal taxes, including capital gains taxes.

Here are the key points related to the Net Investment Income Tax (NIIT) as it pertains to capital gains:

  1. Taxable Investment Income: The NIIT applies to "net investment income," which includes various forms of investment income, such as interest, dividends, rents, royalties, passive rental income, and net capital gains from the sale of investments like stocks, bonds, and real estate.

  2. Thresholds: The NIIT only applies to individuals, estates, and trusts whose modified adjusted gross income (MAGI) exceeds certain thresholds:

    • For individuals: $200,000 for single filers and heads of household, $250,000 for married individuals filing jointly, and $125,000 for married individuals filing separately.
    • For estates and trusts: The threshold is generally much lower, and the NIIT can apply at lower income levels.
  3. Capital Gains: Capital gains are a significant component of net investment income, and the 3.8% NIIT is imposed on the net capital gains amount. Net capital gains represent the difference between total capital gains and total capital losses. Long-term and short-term capital gains are both included in the calculation.

  4. Exclusions: Some types of capital gains may be excluded from the calculation of net investment income and, therefore, not subject to the NIIT. For example, gains from the sale of an active interest in a business or from the sale of a primary residence (subject to certain limitations and requirements) are generally not considered net investment income subject to the tax.

  5. Additional Medicare Tax: The NIIT is sometimes confused with the Additional Medicare Tax, which also affects higher-income taxpayers. The Additional Medicare Tax is a 0.9% tax on earned income (e.g., wages and self-employment income) over specific thresholds. While it's related to Medicare, it's not directly tied to capital gains or investment income.

  6. Reporting and Filing: Taxpayers subject to the NIIT must report and pay the tax on their federal income tax return (e.g., Form 1040). It's essential to consult with a tax professional or refer to the most current IRS guidance for specific reporting requirements and calculations.

The Net Investment Income Tax (NIIT) is designed to help fund Medicare and applies to certain types of investment income, including net capital gains, for individuals, estates, and trusts meeting specific income thresholds. However, it's essential to consider the complexities and nuances of tax law, as well as potential changes in tax regulations, when assessing your specific tax liability.

Net Investment Income Tax and Capital Gains: Understanding the Connection.

The Net Investment Income Tax (NIIT) is a 3.8% tax that applies to net investment income (NII) above certain thresholds. NII includes interest, dividends, capital gains, rental income, and royalty income. Capital gains are profits from the sale of capital assets, such as stocks, bonds, and real estate.

The connection between NIIT and capital gains is that both are forms of investment income. If you sell a capital asset and have a gain, that gain is considered NII and may be subject to NIIT. However, there are some exceptions to this rule. For example, capital gains that are excluded from gross income for regular income tax purposes are also excluded from NII.

Here are some examples of how NIIT and capital gains interact:

  • If you sell a stock at a gain and have a modified adjusted gross income (MAGI) of over $200,000 if filing single or $250,000 if married filing jointly, the gain may be subject to NIIT.
  • If you sell a rental property at a gain and have a MAGI of over $200,000 if filing single or $250,000 if married filing jointly, the gain may be subject to NIIT.
  • If you have a capital loss, you can deduct it from your capital gains and NII.

It is important to note that the NIIT is a separate tax from the capital gains tax. Capital gains taxes are calculated based on your capital gains tax rate, which is 0%, 15%, or 20% depending on your income level. NIIT is calculated based on your NII and your modified adjusted gross income.

If you have any questions about how NIIT and capital gains interact, you should consult with a tax professional.