Hi @Samantha Keogh5! Great question. You can read more about Evergreen Retainers here (our US helpdesk article site): https://smokeball.helpdocsonline.com/evergreenretainer4
In a nutshell, you can set a minimum amount that each matter has to have in the trust account. For example: on my Family Law matter, I never want the trust balance to dip below $1,000. You can also set up reminder emails to be sent out asking clients for additional trust funds if the trust account is close to or below the trust threshold amount.
Let me know if you have any questions!