Inheritances are not considered income for federal tax purposes, whether you inherit cash, investments or property. Any subsequent earnings on the inherited assets are taxable, however. You will be taxed on the interest paid on inherited cash in a bank account, for example, or dividends on inherited stocks or mutual funds.
Any gains when you sell inherited investments or property are generally taxable, but you can usually also claim losses on these sales. State taxes on inheritances vary; check your state's department of revenue, treasury or taxation for details, or contact a tax professional.