Yes, you can do an in-kind transfer from Betterment to Vanguard. This means they will move your holdings as they are now to your Vanguard account. If you choose to sell and buy new funds at Vanguard, you'll pay your taxes then. Keep in mind that any non-Vanguard ETF will have a trading fee when its at Vanguard. What you want to find from Vanguard is the "Brokerage In-Kind Account Transfer Kit." Since Betterment doesn't have traditional account numbers available to view, you may need to get some information from Betterment to complete this (there is actually an account number if you go to the Transfer page and click on "wire transfer," but you may want to confirm that with Betterment).