With regard to my comment about QCDs, I failed to notice that this was in regard to an RMD from a 401(k). You are correct, a QCD cannot be made from a 401(k).
The Required Beginning Date for RMDs from 401(k)s is the same as for IRAs unless the plan agreement specifies otherwise (and I don't know of any reason a plan would specify otherwise). Because 401(k) plans are required to enforce the distribution of RMDs, the 401(k) plan would require the 2018 RMD to be distributed by April 1, 2019.
If you desire to make QCDs in the future, you can roll money from the 401(k) to an IRA and make QCDs from the IRA. However, the 401(k)'sRMD for the year must be satisfied before rolling any amounts over to an IRA. If a rollover to an IRA is done in 2019, the 2019 RMD will have to be satisfied first in addition to any amount of the 2018 RMD that was not yet satisfied.
