Employers considering COVID-19-related layoffs and RIFs right now should add one more item to their checklist of considerations: the possibility of inadvertently triggering a “partial termination” of their tax-qualified retirement plan. Where plan participant numbers decrease substantially, the plan may incur what’s known as a “partial termination.” This is significant because, once triggered, the IRS requires the benefits of all “affected employees” be fully vested. Failure to provide such vesting could put the plan’s tax-qualified…