https://www.kiplinger.com/article/retirement/T040-C000-S004-use-your-nest-egg-to-qualify-for-a-mortgage.html said:
Assets that can be counted under these rules include retirement accounts such as IRAs and 401(k)s, lump-sum retirement account distributions and annuities. "The borrower must be fully vested, and the retirement assets must be in a retirement account that is immediately accessible," says Brad German, a spokesman for Freddie Mac. That means the money cannot be subject to an early-withdrawal penalty and cannot currently be used for income.