It's the same definition we use for small business for other premium rebates. In this case, where the small business has premiums of $20,000 or less that they pay into the EI system, they will not be subject to this. That's the threshold. If they're paying less than $20,000 in premiums, they get a rebate on that as a result.
On May 7th, 2019. See this statement in context.