988 may sound new, but its origins go all the way back to 2001. Originally known as, 1-800-273-TALK (8255), in the year 2020. This shift from the longer form to the shorter form has made it much easier to remember the number in emergencies.
The shorter form draws into similarities to 911. It was officially changed in 2020 when Congress approved the National Suicide Hotline Designation Act of 2020. This change can also reduce the burden of resources from law enforcement and provide specialized help that regular law enforcement may not be capable of providing.
As this is a relatively new change, spreading the world about 988 is the best way to get people to learn more about this special hotline. The more people that know about it, the more likely that it will reach someone that is in need.