If this is a home based business, then you would see the deduction for inventory storage as part of the home office deduction under the business expenses.

The home office section is still there:

• Open (continue) your tax return in TurboTax Online, making sure the Federal tab at the left is selected.
• Click the drop-down arrow next to Tax Tools (lower left side of your screen).
• Select Tools.
• In the pop-up window, select Topic Search.
• In the I'm looking for: box, type sch c.
• In the results box, highlight sch c, then click GO.
• You'll land on Your self-employed work summary. Click Edit/Review next to the line of work.
• On the Here's your work info screen, scroll down under Expenses and locate Home Office. Click Start (or Edit) to enter your information. (Click the attachment below for an example of this screen.) If you don't see Home Office listed, just click "Add expenses for this work" and scroll down to locate it.

If you're using the TurboTax CD/Download (desktop) software, use the Find function to search for "sch c", then click the "Jump to" link.