Traditional tax planning for portfolios has been relatively straightforward - given that the same maximum capital gains tax rate applied regardless of whether someone had $100,000 or $1,000,000 of income, the dominant strategy was simply to defer capital gains as long as possible, and harvest capital losses to further maximize the benefit.
In today's world, however, the introduction of both a new top 20% long-term capital gains tax rate, and a 3.8% Medicare surtax on portfolio income, makes the picture far more complicated. Instead of just having two long-term capital gains tax brackets that reach a cap at $72,500 of income (for married couples), there are now four capital gains tax brackets, that extend as high as $450,000 before the top rate is reached!
The end result of this graduated four-tax-rate structure is that now it's no longer best to just defer capital gains indefinitely, which - just like accumulating a huge IRA - could eventually drive the client's tax rates higher as income is ultimately recognized in the future! Instead, tax planning for portfolios becomes more proactive, where some years it's still best to harvest capital losses, but in other years it's better to harvest the gains, instead!