For N > 2 years, everything in the fund is tax-exempt (even funds contributed less than 2 years ago), but you no longer get the option to refund your contributi

For N > 2 years, everything in the fund is tax-exempt (even funds contributed less than 2 years ago), but you no longer get the option to refund your contributions to cash when moving, you need to wait until you're 50 to start withdrawals.