It didn't sink in when I read: "Mutual Fund Service Members of NSCC
are eligible to use the [ACAT] service on a limited basis, only as the contra-party to a transfer initiated by a broker dealer or a bank for the purpose of re-registering a mutual fund position to or from them directly."http://www.dtcc.com/clearing-services/equities-clearing-services/acats
What this means is that ACAT cannot be used to move assets into a fund held directly with the fund family. Normally not an issue because the fund can do an EFT or wire transfer from your bank. But if it's an IRA transfer, apparently it goes by paper check, and that can take over a week.
This is a downside to using Vanguard's legacy accounts (mutual fund platform) rather than its brokerage accounts. I'm in the process of transferring IRA cash. I had to mail the transfer form to Vanguard (Dec 18th). Vanguard finally processed the form and sent it, apparently by pony express, to the old custodian (Dec 30th). That custodian received the form and cut a paper check (Jan 6). As near as I can tell, it is still the case that "the check is in the mail."
Had I used a Vanguard brokerage account, all of this would have been done electronically in days. Form submission online, funds transferred via ACAT. The cash would have wound up in the Vanguard Government MMF, instead of going directly into the target Vanguard fund. Still, it would have been there weeks earlier, and the money would not be floating around in USPS purgatory, not even earning interest.