The minimum threshold for the specific Shamir scheme used was 2-of-3.

A 2023 case involved a Bitcoin holder who had set up a complex custody arrangement using Shamir's Secret Sharing across three trusted contacts in 2020. By 2023, one contact had moved countries and was unreachable, and a second had died. Only one of the three fragments remained accessible. The minimum threshold for the specific Shamir scheme used was 2-of-3. With only one fragment available, the entire arrangement was unrecoverable. The case illustrated how Shamir's Secret Sharing—designed to prevent single points of failure—created a different failure mode when the fragment holders themselves were unavailable.