I was TN-certified. Do I need to be accredited now that I am an IBO?

Does my TN certification transfer?

Yes. If you used to be TN certified, you need to get accredited when you switch to ACN and become an IBO. This accreditation must be renewed annually, and you must score a 90% to pass. 

You can get started at https://acncompass.com/impact-health-sharing/.