https://medium.com/@jproco/you-need-250-000-to-start-a-compa...
This is what Medium calls a "friend link" and it should work for anyone whether a Medium member or not.
"You’ve reached the end of your free member preview for this month. Become a member now for $5/month to read this story and get unlimited access to all of the best stories on Medium."
"I can confirm this is the correct friend link. If your readers access the story via this link, they will always be able to view it, even if they are out of their free monthly previews. There aren't really any limits on this."