Very useful information. My IRA distribution in question was a Roth conversion, so it's considered a rollover (per page 22 of IRS Publication 590-A for 2022 tax year, the latest version available on IRS website). Therefore, it met one of the exceptions shown in Publication 590-B and Vanguard had to include those conversions in 2023 even though it settled in 2024. Vanguard did issue me a corrected 1099-R after I brought up the issue. Luckily, I hadn't filed tax returns yet.
It's different for RMD calculation. Since that Roth conversion settled in 2024, its value must be included in the 2023 year-end IRA account value.
10-day margin you mentioned about is terrible! I don't know why it takes Vanguard so long to settle trades. Some of my Vanguard mutual fund trades took 8 days to settle. That makes my year-end tax planning very difficult as I would not know if I have taken enough RMD or reached my Roth conversion goal.
Vanguard is supposed to settle mutual fund trades on T+1 and stock/ETF trades on T+2. It takes Schwab and Fidelity 1 to 2 business days to settle trades. I wonder if Vanguard violates the SEC regulations here.
