Hello, dmventre. 

QuickBooks Desktop is really great accounting software. However vendor insurance alert feature is one of our product limitation in the system. You may consider upgrading to QuickBooks Desktop Premier Contractor Edition. This way, you'll be able to use these options and have a way to track vendor insurance.  

Here's how you can add the fields:

1. Tap Vendors on the top menu.
2. Choose Vendor Center. 
3. Double click the vendor's name.
4. Tick the Additional Info tab.
5. Tap the Define Fields button.
6. Enter the info in the Label column and place a checkmark for Vend column.
7. Hit OK.
8. Type the expiration date in the Custom Fields section.
9. Click OK.

Then, we can create a reminder for vendor insurance alert. 

Here's how:

1. Click Company on the top menu.
2. Pick Reminders.
3. Tick the Plus icon on the top right side.
4. Enter the details in the Type, Priority, With, Due and Time fields.
5. Type the description in the Details section.
6. Choose Active in the Status field.
7. Tap OK. 

I have a link here that provides you with articles about managing expenses and vendors in your account: Expenses and vendors 

I'm all ears here. Let me know if you have further Question about vendor insurance alert.