NUA comes into play if you take a total payout from a company retirement plan that includes appreciated employer securities. Rather than make a tax-free rollover of the entire amount to an IRA, you can roll the stock into a taxable account and owe tax only on the stock’s value when you acquired the shares. The Net Unrealized Appreciation that accrued while the stock was inside the plan will not be taxed until you ultimately sell the stock. At that point, the profit can qualify for special long- term capital gain treatment. If you rolled the stock into an IRA, all appreciation would be taxed as ordinary income when withdrawn, at your top tax rate.