Understanding IRS Rules on Mold Remediation Deductions

Is mold remediation tax deductible?

The IRS generally does not allow homeowners to deduct mold remediation expenses as a personal expense, but they can be deductible if the work is part of a qualified improvement to a rental property or if the mold is caused by a sudden, unexpected event covered by insurance.

When it qualifies for a deduction

For rental properties, remediation costs are treated as a repair or a capital improvement. Repairs that keep the property in ordinary operating condition can be deducted in the year incurred. If the work adds value, prolongs useful life, or adapts the building to a new use, it must be capitalized and depreciated over the appropriate recovery period.

Casualty loss exception

If mold results from a sudden, unforeseen event—such as a burst pipe or a storm—and the damage is not covered by insurance, the expense may be claimed as a casualty loss on Schedule A, subject to the $100 per‑event floor and the 10% of adjusted gross income limitation.

Insurance reimbursements

When insurance pays for remediation, the deductible portion is reduced by the reimbursement amount. Any excess reimbursement that exceeds the actual cost must be reported as income.

How to claim the expense

For a rental, report repair costs on Schedule E, line 14, and capital improvements on Form 4562 for depreciation. For a casualty loss, use Form 4684 and transfer the net loss to Schedule A. Keep detailed invoices, photos, and proof of the cause of the mold to substantiate the claim.

Key points at a glance

• Homeowners: generally not deductible.
• Rental property: deductible as repair or depreciated as improvement.
• Casualty loss: possible if caused by sudden, unexpected event and not reimbursed.
• Insurance payments reduce the deductible amount.