Hello Jack Loomis,
Thank you for posting your query in the Microsoft Q&A Community.
If you are looking at limiting access of some specific users to MS applications, you need to leverage the Named Locations feature in Conditional Access Policies. This will allow you to restrict access of selected or all users based on their IPs or Locations to whatever applications in your environment. Please note that Named Location only works with the IP address range.
Follow these links for more information about creating the named location and conditional access policies where users' access will be restricted.
https://learn.microsoft.com/en-us/entra/identity/conditional-access/concept-assignment-network
Let me know if further assistance is required
Babafemi