ISOs & NSOs: Everything You Need to Know About Your Stock Options

Stock options can be one of the biggest financial opportunities of your career. But they can also be one of the most expensive mistakes. These are complex financial instruments that let employees take part in the growth of the company they work for. But without the proper insights on how to handle them, they can cost you a fortune.

The difference usually isn't how the stock performs. It comes down to how they are handled from the tax perspective. ISOs and NSOs may look exactly the same in your equity portal, but the rules on how to handle them are completely different. Exercise or sell the wrong amount and you can owe six figures in tax on stock you never sold. Wait too long, and the options can expire worthless.

Here's how each one works, where people go wrong and the checklist that can help you be prepared:

How stock options work

A stock option gives you the right to buy your company’s stock at a fixed price, aka the strike price. If the stock trades above that price, the difference is called the spread. That spread is your profit, and it’s also what gets taxed when you eventually sell or exercise.

Similar to RSUs, options usually vest throughout the year, and over several years. Once they vest, you can exercise them, which means paying the strike price to get the shares. Most options expire 10 years after they’re granted. If you leave your job, you often get just 90 days to exercise.

NSOs: taxed when you exercise

Non-qualified stock options (NSOs) are the simpler of the two. When you exercise, the spread is taxed as ordinary income, just like your salary: taxed for Social Security and Medicare. Your cost basis in the shares becomes the stock price on the day you exercise. Any growth after that is a capital gain or loss when you sell.

The part that trips people up is typically the withholding. Companies almost always withhold 22% federal on the spread. The issue with this is that most people with meaningful options are in the 32%, 35% or 37% bracket, so there ends up being a large withholding gap.

Let's look at a quick example: Let's say you exercise options with $400k worth of gains - again, called "the spread." On this amount, typically only about $88k will be withheld, but if you're in the 37% bracket, you will owe closer to $148k on this amount. There's a ~$60k difference between what you stashed away for taxes and what you actually owe, and that bill comes due in April. Some people let this happen over and over again, so they dread April. The right financial partner helps you build a plan and a system so that you're prepared for a situation like that, rather than reacting to it.

ISOs: better tax treatment, bigger traps

Incentive stock options (ISOs) have the opportunity to be taxed much more favorably, but there are more stringent rules that must be followed. If they aren't followed, it can result in a much higher tax bill.

Let's say you have ISOs and you work with an advisor to determine it's a good time to exercise them. If you sell them right away, this is called a "disqualifying disposition" and your ISOs are now taxed as NSOs (remember, at a higher rate). If you exercise and decide to keep them, you don’t owe regular income tax when they're exercised. The trick is you have to hold the shares more than two years from the grant date and more than one year from the exercise date, and the entire gain is taxed at long-term capital gains rates when you sell. For a high earner, that’s 20% (or most likely 23.8% when including NIIT for high earners) instead of 37%.

For example, you exercise 10,000 ISOs at a $10 strike price and later sell at $60 after meeting both holding periods. Your $500,000 gain is taxed at 20%, about $100,000 instead of $185,000. Without a specialist looking at your situation, you could miss out on significant tax savings.

The trap is the alternative minimum tax (AMT), and it’s the reason ISO holders can owe six figures in tax without ever selling a share. The spread on ISOs you exercise and hold counts as income for AMT purposes. What does that mean? Let’s break it down: say you exercise ISOs with a $1 million spread. You can owe a six-figure AMT bill that year on shares you haven’t sold. If the stock drops before you sell, you still owe tax on a gain that no longer exists. That’s because AMT is a separate tax calculation that runs alongside the regular one, and you pay whichever is higher. The regular system ignores your ISO spread, but AMT taxes it at up to 28%.

The good news is it can be managed. An AMT projection shows how many ISOs you can exercise each year before AMT kicks in. Selling the shares in the same year you exercise avoids AMT entirely. And AMT you pay on ISOs can often be recovered as a credit in future years.

The moment you've been waiting for...

Here's the checklist I'd use to make sure I had my ducks in a row:

• List every grant you have: ISO or NSO, strike price, number of shares, vest dates and expiration date.

• Write down every deadline, including the 90-day window if you leave your job. Check it before you give notice, not after.

• Before exercising NSOs, figure out your real tax rate and set aside the gap between that and the 22% your company withholds.

• Before exercising ISOs, run an AMT projection so you know how many shares you can exercise without a surprise bill.

• If you’re holding ISO shares for the lower rate, put both holding period dates on your calendar. Selling one day early changes the tax.

• When you sell, check the cost basis on your 1099-B so you aren’t taxed twice on the same income.

Let's get serious

Equity compensation - whether it's stock options, RSUs or straight up equity - could be the biggest asset you ever acquire. It can also turn into the biggest tax bill and the biggest headache you've ever had. That's why, especially for complex situations like NSOs and ISOs, it makes sense to consult an expert.

Luckily, Reliant Wealth Advisory specializes in these types of situations. So you can either continue risking an expensive mistake yourself, or you can make the right decision to call an equity comp specialist today.

Book your free strategy session here.