401-k Plan Audits

When is a 401-k plan (safe harbor) required to be audited by an independent CPA Firm?  I know it used to be 100 employees but I think it recently changed to the amount of account balances?  Any information is appreciated.

Effective for plan years beginning in 2023 and later, the audit requirement applies to plans with at least 100 participants with account balances on the first day of the year. The 80-120 rule still applies, so if the plan filed as a small plan in 2022, they would not have to have an audit until they have more than 120 participants with account balances on the first day of the year.