If you invest in activities where you don't actively participate, such as rental properties or limited partnerships, these are considered passive activities. The losses you incur from these investments can only be used to offset income from similar passive investments. Unfortunately, you can't use these losses to reduce your taxable income from other sources, like your salary, interest, dividends, or capital gains. There are some exceptions to this rule, however. Real estate professionals, for example, may be able to deduct losses from their investments against their ordinary income. Additionally, if you're an individual who actively participates in rental real estate, you may be able to deduct some losses against your ordinary income. If you have passive losses that you can't use in the current year because you don't have enough passive income to offset them, don't worry. You can carry these losses over to future years, where they may be deductible against the passive income you earn in those years.