How do you justify a GMAT waiver?

 To get a GMAT waiver!  So, For that you need to show that your work and school experiences already prove you can handle the MBA program. Tell them about your job, especially if you’ve had to solve tough problems or manage budgets. 

If you’ve taken any special courses that show off your business skills, mention those too. And if you did really well in college, that could help a lot too. 

Just show them you've got the skills they’re testing for with the GMAT.