Quick overview

This guide explains the current IRS rules for claiming casualty and theft losses on federal returns, how to calculate the deductible amount, where to report the loss, and practical documentation and planning tips. It reflects rules in effect through 2025, including the Tax Cuts and Jobs Act (TCJA) limitation that narrowed personal casualty loss deductions to federally declared disaster losses (see IRS Topic No. 515 and Publication 547).

Sources: IRS Topic No. 515 and IRS Publication 547, Casualties, Disasters, and Thefts.

When is a loss deductible?

  • Personal casualty and theft losses: For tax years after 2017 through 2025, personal casualty and theft losses are deductible only if they are the result of a federally declared disaster (per the TCJA). In practice, that means if your home, car, or personal property is damaged or destroyed in an event for which the President (or the federal government) issues a disaster declaration, you may be able to claim a deduction.
  • Business and income-producing property: Losses that are incurred in a trade or business or in a transaction entered into for profit (including rental property) are still deductible under the ordinary loss rules and are not limited to federally declared disasters. These losses are reported using business tax forms or Form 4684, depending on the situation.

(See IRS Publication 547 for details and examples.)

Which form and lines to use

  • Form 4684, Casualties and Thefts, is used to compute gains or losses from casualty or theft events. Part A of Form 4684 covers personal-use property; other parts address business or income-producing property. The result for personal-use property flows to Schedule A (itemized deductions) and is subject to the $100-per-event floor and the 10% of AGI limitation described below. For business losses, the amount generally flows to the appropriate business schedule (Schedule C, Schedule E, or the corporate return).

Official guidance: About Form 4684 — IRS and IRS Publication 547.

How to compute the deductible amount (step-by-step)

For a personal-use property loss that qualifies (a federally declared disaster), follow these steps commonly used by tax preparers and described in IRS guidance:

  1. Determine the loss amount: the loss is the lesser of (a) the property’s adjusted basis before the casualty or (b) the decrease in fair market value (FMV) caused by the casualty.
  2. Subtract any insurance or other reimbursement you actually received or expect to receive.
  3. Reduce the remainder by $100 for each separate casualty or theft event.
  4. Combine all qualifying losses for the year (after the $100 reduction) and then reduce the total by 10% of your adjusted gross income (AGI). The remaining balance is the deductible amount that you report on Schedule A.

Example (personal-use property):

  • Adjusted basis or cost of an item before casualty: $20,000
  • FMV decrease due to the casualty: $18,000 (so use $18,000)
  • Insurance reimbursement: $3,000
    Preliminary loss: $18,000 − $3,000 = $15,000
    Subtract $100 per event: $15,000 − $100 = $14,900
    Assume AGI = $60,000 → 10% AGI = $6,000
    Deductible amount = $14,900 − $6,000 = $8,900 (reported on Schedule A via Form 4684)

Notes:

  • If reimbursements exceed the loss, you may have a casualty gain instead of a loss and must report it.
  • For business or income-producing property, the $100 and 10% AGI reductions do not apply; ordinary-loss rules apply instead.

When do you claim the deduction?

  • Casualty loss: generally in the year the casualty occurred.
  • Theft loss: generally in the year the theft is discovered.

If you receive delayed insurance or other reimbursements in a later year, you may need to amend the earlier return or report a gain in the year you received the reimbursement. See Publication 547 and Form 4684 instructions for timing rules and examples.

Special situations and practical considerations

  • Federally declared disasters: Keep a copy of the FEMA or federal disaster declaration (or the IRS announcement) to document that the event qualified as a federally declared disaster. The IRS typically issues guidance for major disasters that specifies relief and deadlines.

  • Insurance proceeds, grants, and disaster payments: Insurance proceeds reduce your deductible loss dollar-for-dollar. Some disaster assistance (like certain qualified disaster relief payments) may be excluded from income but still reduce tax attributes — treat each program carefully and document how you used any grants or relief funds. See our article on Federal Tax Treatment of Disaster-Related Insurance Proceeds for practical examples.

  • Business vs. personal property: Distinguish whether property is personal use, business, or income-producing — the tax treatment is different. Business losses usually reduce taxable income directly and are often claimed on business returns (Schedule C for sole proprietors, Form 1065/1120, or Schedule E for rental property).

  • Reconstructed records: If documents were lost in the disaster, rebuild a record using photos, contractor bids, insurance estimates, canceled checks, and contemporaneous notes. Our guide on Reconstructing Records After a Disaster has a practical checklist.

Common mistakes to avoid

  • Assuming all losses are deductible. Since TCJA, most personal casualty losses are deductible only if tied to a federally declared disaster.
  • Filing the wrong form or failing to route the calculated loss correctly to Schedule A or business forms.
  • Forgetting to subtract insurance reimbursements or to apply the $100 per-event and 10% AGI reductions (for personal losses).
  • Failing to document the event (police reports for theft, photos, contractor estimates, FEMA or federal declaration documents).

Real-world examples

1) Homeowner after a hurricane (federally declared): Roof damaged; repair estimates show FMV decline of $40,000; insurance pays $25,000; AGI $80,000.

  • Loss after insurance = $15,000; after $100 = $14,900; after 10% AGI = $14,900 − $8,000 = $6,900 deductible on Schedule A.

2) Small business equipment theft (not personal): $10,000 adjusted basis, fully uninsured. Business deducts $10,000 as an ordinary loss on its business return (no $100 or 10% AGI limits). The business documents police report and replacement costs.

3) Theft discovered after the year of occurrence: If you discover a theft in a later year, deduction is claimed in year of discovery; retain the police report date as the discovery date.

Documentation checklist (what the IRS will expect)

  • Police report (theft or vandalism)
  • Insurance claim file, correspondence, and settlement statements
  • Photographs or video of damage
  • Contractor estimates, receipts, and canceled checks for repairs/replacement
  • Appraisals for items of significant value
  • FEMA or federal disaster declaration documentation (for personal losses)
  • Notes showing the date and circumstances of discovery for thefts

Professional tips

  • Document everything immediately. Evidence assembled within days or weeks of the event is strongest.
  • Check for other tax relief after disasters: the IRS routinely announces filing and payment relief for disaster areas; those announcements can affect deadlines and filing procedures. See our guide to Tax Filing Options for Victims of Natural Disasters.
  • Review insurance and mitigation choices with a CPA before accepting final settlement if you plan to claim a deduction; settlement timing and amounts affect the deductible loss and potential gain recognition.
  • For business owners, claim the loss on the correct business return and maintain separate records from personal property.

Frequently asked quick answers

  • Are personal casualty losses deductible for non-disaster events? Generally no, unless related to a federally declared disaster (TCJA limitation). (IRS Topic No. 515)
  • Does the $100 and 10% AGI rule still apply? Yes — for personal casualty and theft losses that qualify, you must reduce each event by $100 and then subtract 10% of AGI from the total.
  • What if I receive insurance later? If you receive additional reimbursement after claiming the loss, you may need to amend the earlier return or report a gain in the later year.

Closing and disclaimer

The rules for casualty and theft loss deductions are technical and fact-specific. This article summarizes current federal rules and common scenarios but is educational only — it is not individualized tax advice. For a precise calculation, return filing, or to handle difficult cases (large losses, mixed personal/business property, or unusual disaster relief payments), consult a qualified tax professional or CPA.

Authoritative sources: IRS Topic No. 515 and IRS Publication 547 (linked above). Additional practical resources on FinHelp: our posts on rules after recent disaster law changes, disaster-related insurance proceeds, and tax filing options for disaster victims.

If you need personalized assistance, contact a local CPA or tax attorney who can review records, insurance settlements, and the applicable federal disaster determinations.