For losses of trade or business property, or property used to produce rentals or royalties, once you've calculated the amount of your loss and subtracted the amount of your reimbursement, the remainder is your deductible loss (or gain).
For losses of income-producing property that is not described above (for example, investments such as stocks, bonds, gold, silver, and works of art), your casualty losses are added to your itemized miscellaneous deductions. All of these deductions are added together, 2 percent of your adjusted gross income is subtracted, and the remainder is your deductible amount.
Limits on personal losses. For thefts or casualties of personal or family property, your deductible loss is much more strictly limited. After calculating the amount of your loss and subtracting any reimbursements, you must subtract $100 for each casualty, theft, or accident you suffered during the year, regardless of the number of items that were damaged or destroyed during the event.
If you are married filing jointly, a single $100 reduction applies for each event, but if you are filing separately, each spouse who claims a loss must subtract $100, for a total of $200 per event for jointly owned property. If only one spouse owned the property at issue and you are filing separately, that spouse is the only one who can claim a deduction (and must apply the $100 reduction).
After the first $100 is subtracted, you're not in the clear yet: you must again reduce your deductible loss by a full 10 percent of your adjusted gross income as shown on Line 33 of your Form 1040. As a result, small personal casualty losses are unlikely to bring you any tax benefits.
Mixed-use property. If you suffered damage to your home, part of which
you were using as a home office, or to your car, which you sometimes used for
business, you have mixed-use property and your loss must be proportionately
divided between the two types of usage. You will actually treat the event as if
it were two separate losses. The $100 and 10 percent of AGI reduction applies
only to the personal portion of the loss. Some special considerations apply in
the case of home