What are the tax implications of exercising options early?
Despite a fair number of views, no one besides @mbhunter answered, so I'll gather the findings of my own research here. Hopefully, this will help others in similar situations. If you spot any errors, please let me know! The difference is whether your options qualify as incentive stock options (ISOs), or whether they are non-qualifying options. If your options meet all of the criteria for being ISOs (see here), then (a) you are not taxed when you exercise the options.  You treat the sale of the underlying stock as a long term capital gain, with the basis being the exercise price (S). There is something about the alternative minimum tax (AMT) as they pertain to these kinds of options.  Calculating your AMT basically means that your ISOs are treated as non-qualifying options.  So if your exercise bumps you into AMT territory, too bad, so sad. If you exercise earlier, you do get a clock ticking, as you put it, because one of the caveats of having your options qualify as ISOs is that you hold the underlying stock (a) at least two years after you were granted the options and (b) at least one year after you exercise the options.
"I'm adding to @Dilip's basic answer, to cover the additional points in your question.  I'll assume you are referring to publicly traded stock options, such as those found on the CBOE, and not an option contract entered into privately between two specific counterparties (e.g. as in an employer stock option plan). Since you are not obligated to exercise a call option you purchased on the market, you don't need to maintain funds on account for possible exercising.  You could instead let the option expire, or resell the option, neither of which requires funds available for purchase of the underlying shares. However, should you actually choose to exercise the call option (and usually this is done close to expiration, if at all), you will be required to fund your account much like if you bought the underlying shares in the first place.  Call your broker to determine the exact rules and timing for when they need the money for a call-option exercise. And to expand on the idea of ""cancelling"" an option you purchased: No, you cannot ""cancel"" an option contract, per se.  But, you are permitted to sell the call option to somebody else willing to buy, via the market.  When you sell your call option, you'll either make or lose money on the sale – depending on the price of the underlying shares at the time (are they in- or out- of the money?), volatility in the market, and remaining time value.  Once you sell, you're back to ""no position"".  That's not the same as ""cancelled"", but you are out of the trade, whether at profit or loss. Furthermore, the option writer (i.e. the seller who ""sold to open"" a position, in writing the call in the first place) is also not permitted to cancel the option he wrote.  However, the option writer is permitted to close out the original short position by simply buying back a matching call option on the market.  Again, this would occur at either profit or loss based on market prices at the time.  This second kind of buy order – i.e. made by someone who initially wrote a call option – is called a ""buy to close"", meaning the purchase of an offsetting position.  (The other kind of buy is the ""buy to open"".) Then, consider: Since an option buyer is free to re-sell the option purchased, and since an option writer (who ""sold to open"" the new contract) is also free to buy back an offsetting option, a process known as clearing is required to match remaining buyers exercising the call options held with the remaining option writers having open short positions for the contract.  For CBOE options, this clearing is performed by the Options Clearing Corporation.  Here's how it works (see here): What is the OCC? The Options Clearing Corporation is the sole issuer of all securities   options listed at the CBOE, four other U.S. stock exchanges and the   National Association of Securities Dealers, Inc. (NASD), and is the   entity through which all CBOE option transactions are ultimately   cleared. As the issuer of all options, OCC essentially takes the   opposite side of every option traded. Because OCC basically becomes   the buyer for every seller and the seller for every buyer, it allows   options traders to buy and sell in a secondary market without having   to find the original opposite party.   [...]   [emphasis above is mine] When a call option writer must deliver shares to a call option buyer exercising a call, it's called assignment.  (I have been assigned before, and it isn't pleasant to see a position called away that otherwise would have been very profitable if the call weren't written in the first place!) Also, re: ""I know my counter party cannot sell his shares"" ... that's not strictly true.  You are thinking of a covered call.  But, an option writer doesn't necessarily need to own the underlying shares.  Look up Naked call (Wikipedia).  Naked calls aren't frequently undertaken because a naked call ""is one of the riskiest options strategies because it carries unlimited risk"".  The average individual trader isn't usually permitted by their broker to enter such an order, but there are market participants who can do such a trade. Finally, you can learn more about options at The Options Industry Council (OIC)." Does this technically mean that she has to pay AMT on $400,000? Yes. Well, not exactly 400,000. She paid $1 per share, so 390,000. And if so, is %28 the AMT for this sum? (0.28 * $400,000 = $112,000)?   Or does she have to include her salary on top of that before   calculating AMT? (Suppose in the fake example that her salary is   $100,000 after 401k). All her income is included in calculating the AMT, minus the AMT exemption amount. The difference between the regular calculated tax and the calculated AMT is then added to the regular tax. Note that some deductions allowed for the regular calculation are not allowed for the AMT calculation. How does California state tax come into play for this? California has its own AMT rules, and in California any stock option exercise is subject to AMT, unless you sell the stock in the same year. Here's a nice and easy to understand write up on the issue from the FTB. When would she have to pay the taxes for this huge AMT? Tax is due when income is received (i.e.: when you exercise the options). However, most people don't actually pay the tax then, but rather discover the huge tax liability when they prepare to submit their tax return on April 15th. To avoid that, I'd suggest trying to estimate the tax and adjust your withholding using form W4 so that by the end of the year you have enough withheld. Suppose in the worst case, the company goes completely under. Does she   get her massive amounts of tax back? Or if it's tax credit, where can   I find more info on this? That would be capital loss, and only up to $3K a year of capital loss can be deducted from the general income. So it will continue offsetting other capital gains or being deducted $3K a year until it all clears out. Is there any way to avoid this tax? (Can she file an 83b election?) You asked and answered. Yes, filing 83(b) election is the way to go to avoid this situation. This should be done within 30 days of the grant, and submitted to the IRS, and a copy attached to the tax return of the grant year. However, if you're considering exercise - that ship has likely sailed a long time ago. Any advice for Little Susie on how she can even afford to pay that   much tax on something she can't even sell anytime soon? Don't exercise the options? Should she   take out a loan? (e.g. I've heard that in the extreme case, you can   find angel investors who are willing to pay all your taxes/strike   price, but want 50% of your equity? I've also heard that you can sell   your illiquid shares on SecondMarket?) Is she likely to get audited by IRS for pulling something like this? You can take a loan secured by shares you own, there's nothing illegal in it. If you transfer your shares - the IRS only cares about the taxes being paid, however that may be illegal depending on the terms and the conditions of the grant. You'll need to talk to a lawyer about your situation. I suggest talking to a licensed tax adviser (EA/CPA licensed in your State) about the specifics concerning your situation. The CBOE had a great article on this. I will search for it and edit. The normal dividends are not adjusted. Which is why you see early exercise of just out of the money options sometimes. To get that dividend. A special dividend, say a $50 stock with $1/yr dividend but now has a $3 one time dividend would likely result in an option strike adjustment. "Not necessarily.  The abbreviation ""ESOP"" is ambiguous.  There are at least 8 variations I know of: You'll find references on Google to each of those, some more than others.  For fun you can even substitute the word ""Executive"" for ""Employee"" and I'm sure you'll find more.  Really. So you may be mistaken about the ""O"" referring to ""options"" and thereby implying it must be about options.  Or, you may be right.  If you participate in such a plan (or program) then check the documentation and then you'll know what it stands for, and how it works.  That being said: companies can have either kind of incentive plan: one that issues stock, or one that issues options, with the intent to eventually issue stock in exchange for the option exercise price. When options are issued, they usually do have an expiration date by which you need to exercise if you want to buy the shares. There may be other conditions attached. For instance, whether the plan is about stocks or options, often there is a vesting schedule that determines when you become eligible to buy or exercise. When you buy the shares, they may be registered directly in your name (you might get a fancy certificate), or they may be deposited in an account in your name. If the company is small and private, the former may be the case, and if public, the latter may be the case. Details vary. Check the plan's documentation and/or with its administrators." Purchasing stock doesn't affect your immediate taxes any more than purchasing anything else, unless you purchase it through a traditional 401k or some other pre-tax vehicle. Selling stock has tax effects; that's when you have a gain or loss to report. While the 55 exception noted by Joe and JB makes this less of a worry, it's worth noting that to retire early most people would need additional investments beyond a maxed out 401(k).  As most people make more money later in life it is generally worth putting what you can in a 401(k) now and later when your savings would max out a 401(k) then you can start adding money to accounts that are not tax-advantaged.  These additional funds can be used during the bridge period. Run the numbers yourself as these assumptions won't be true for all individuals, but this may be the piece you are missing. For a deep in the money, it almost makes no difference because the intrinsic value, the price of the option, is seldom far above the liquidation value, the price of the underlying less the strike price. For an at the money, ceteris paribus, an early exercise would immediately cut the value of the option to 0; however, life is not so simple as JB King has shown. Purely theoretically, for an at or near the money option, an early exercise will be an instantaneous cost because the value after exercise is less than the previously trading or implied option price. Options granted by an employer to an employee are generally different that the standardized options that are traded on public stock option exchanges.  They may or may not have somewhat comparable terms, but generally the terms are fairly different. As a holder of an expiring employee option, you can only choose to exercise it by paying the specified price and receiving the shares, or not.  It is common that the exercise system will allow you to exercise all the shares and simultaneously sell enough of the acquired shares to cover the option cost of all the shares, thus leaving you owning some of the stock without having to spend any cash.  You will owe taxes on the gain on exercise, regardless of what you do with the stock. If you want to buy publicly-traded options, you should consider that completely separately from your employer options other than thinking about how much exposure you have to your company situation.  It is very common for employees to be imprudently overexposed to their company's stock (through direct ownership or options).