In 2027 my income will cross into what the IRS deems as a “highly compensated employee” or a HCE at $170k+.

As I understand it, there is some risk in contributing to a Mega Backdoor Roth as an HCE. If my employer fails the actual Contribution Percentage test, and I have already moved this money to my Roth IRA by way of an in-service rollover, I could have to unwind the rollover, and then unwind the contribution which would get very very messy.

Is this really a concern? My employer has a few thousand professional services employees I would guess most make $100k+.

I suppose I could forgo the in-service rollover and keep the money in 401k plan until the end of the next year just in case the plan fails ACP testing.

Is this a legitimate concern of people using a MBDR?