In Vanguard's case, the TD funds generally make sense starting out given their lower minimum investment requirements ($1000 vs $3000 for most others). Once you

In Vanguard's case, the TD funds generally make sense starting out given their lower minimum investment requirements ($1000 vs $3000 for most others). Once you reach $10-20k and can starting using Admiral funds, then you can switch to a three-fund portfolio and take advantage of lower ERs.