Airbnb sent a 1099-K but I meet the 14-day rule. After adding the income, where do I subtract it as an adjustment and note the 14-day exception?

Since your property was rented less than 14 days, no entry is required to be reported on Schedule E Rental Income and Expenses.  However, if you enter the income reported on Form 1099-K in the normal place where this data would be entered, TurboTax is going to take you through the Schedule E section as well.  

Instead, use the steps below to report the income and report the same amount as a negative adjustment.  Ignore any messaging that says do not enter Form 1099-K in this manner to avoid going through Schedule E.

• Go to the Income section of your return
• Scroll to the Less Common Income category
• Click Start or Update beside Miscellaneous Income, 1099-A, 1099-C
• Scroll to the bottom of that section and click Start or Update beside Other reportable income
• Answer Yes
• Enter your description and amount for the income you received
• Enter your description and a negative amount for the income you received

The end result is that no additional income is reported on your return, but there are two income entries shown on Schedule 1 line 8z.