Do you collect art, jewelry, coins, or stamps? Or maybe your passion is action figures or sports memorabilia. Whatever the focus, your collection could be valuable—and donating all or part of it to a museum or another nonprofit organization could earn you a substantial tax deduction. If you play your cards right, you may be able to write off the full value of your donation immediately.

The basic rule is that you can deduct the fair market value (FMV) of a collectible item you give to charity if selling it would have produced a long-term capital gain. Therefore, if you've owned the property for more than one year, the amount you deduct can include the item's appreciation in value since you acquired it. And you never will be taxed on that gain.

On the other hand, for a collectible you've owned for a year or less, your deduction is limited to your "basis" in the property (usually, your initial cost). These are essentially the same rules that apply to donations of securities.