Per IRS Instructions for Schedule A Itemized Deductions, on page A-12:

Casualty and Theft Losses

Line 15

Complete and attach Form 4684 to figure the amount of your loss. Only enter the amount from Form 4684, line 18, on line 15.

On page A-13:

CAUTION! Don't enter a net qualified disaster loss from Form 4684, line 15, on line 15. Instead, enter that amount, if any, on line 16. See Line 16, later, for information about reporting a net qualified disaster loss.

You can only deduct personal casualty and theft losses attributable to a federally declared disaster to the extent that:

1. The amount of each separate casualty or theft loss is more than $100, and
2. The total amount of all losses during the year (reduced by the $100 limit discussed in (1)) is more than 10% of the amount on Form 1040 or 1040-SR, line 11.

To review or modify these entries in your TaxAct^® return:

1. From within your TaxAct return (Online or Desktop), click Federal. On smaller devices, click in the upper left-hand corner, then click Federal.
2. Click Itemized or Standard Deductions in the Federal Quick Q&A Topics menu to expand, then click Casualty or theft losses.
3. Continue with the interview process to enter all of the appropriate information.
4. On the screen titled Do you want to review your casualty and theft loss information?, click Yes.
5. Click + Add Form 4684 Section A to create a new copy of the form or click Edit to review a form already created.

TaxAct will use the higher of your Itemized Deductions or the Standard Deduction for your filing status to maximize the tax benefit to you. If you do not itemize deductions, you cannot take the casualty and theft deduction and Form 4684 Casualties and Thefts will not print with your return; however, you can print just that form to review the calculations if you wish.

If you have a casualty loss from a disaster that occurred in an area declared by the President to be a federal disaster area, refer to IRS Publication 547 Casualties, Disasters, and Thefts for more information. In the case of a federally declared disaster, an affected taxpayer can call 1-866-562-5227 to speak with an IRS specialist trained to handle disaster-related issues. For additional information, refer to the IRS.gov has the Latest Information for Taxpayers in Disaster Areas website.

Note that any link in the information above is updated each year automatically and will take you to the most recent version of the document at the time it is accessed.