The 475(f) Trader Election: The March 15 Deadline You Can't Miss

$3,000. That is the annual capital loss you are stuck deducting against ordinary income if you trade actively, blow through the $3,000 net capital loss ceiling under §1211(b), and never made the §475(f) mark-to-market election. A trader who loses $180,000 in a bad year without the election writes off $3,000 and carries the other $177,000 forward at $3,000 a year. The election converts those trading gains and losses to ordinary, which removes the cap. But it is a deadline election, and the deadline is not on your radar unless someone puts it there.

Here is the sequence, in order.

Step 1: Confirm you actually qualify as a trader

The election is only available to a "trader in securities or commodities," not an investor. This is a facts-and-circumstances test under case law, not a checkbox. The IRS looks at whether your activity is frequent, regular, and continuous, whether you seek to profit from short-term swings rather than dividends and appreciation, and how much time you devote to it. There is no statutory number of trades, but the pattern courts and the IRS credit involves near-daily activity across most of the trading days in the year, hundreds of trades, short holding periods, and the activity being pursued like a business.

If you are a buy-and-hold investor, or you trade heavily for two months and go quiet, you are not a trader, and the election does not apply to you. Get this wrong and the mark-to-market treatment you claimed unwinds on exam.

Step 2: Understand what §475(f) actually does

Trader Tax Status (TTS) and the §475(f) election are two separate things. TTS lets you deduct trading business expenses on Schedule C. The §475(f) election is a further, optional step that changes how your gains and losses are characterized.

Once elected, under §475(f)(1):

• You mark all covered positions to market on the last business day of the year. Unrealized gains and losses are recognized as if you sold at year-end fair market value.
• Gains and losses become ordinary, reported on Form 4797, not capital gains on Schedule D.
• The $3,000 capital loss limitation under §1211(b) no longer applies to your trading results, because they are no longer capital.
• The wash sale rules of §1091 no longer apply to your marked positions, since there is nothing to defer when everything is already recognized at year-end.

The tradeoff is real: you give up long-term capital gains rates on trading positions. For someone whose strategy actually produces net gains taxed at 0/15/20 percent, electing mark-to-market can cost money, because ordinary rates run higher. The election helps the trader who has losses or churns everything short-term anyway. It hurts the trader sitting on appreciated long-term winners.

Step 3: Note the deadline, because it is the whole point

For an existing individual taxpayer, the §475(f) election for a given year must be made by the unextended due date of the prior-year return. For a calendar-year individual, that is the April filing deadline for the return of the year before the election year, and the election takes effect for the current year.

Read that twice. To have mark-to-market apply to 2025, you make the election by the 2024 return's unextended due date in April 2025. An extension of time to file your return does not extend the time to make the election. This procedure comes from Rev. Proc. 99-17, which governs how the §475(f) election is made.

For a partnership or S corporation, the entity makes the election, and the relevant date is the unextended due date of the entity's prior-year return, which is March 15 for a calendar-year pass-through. That March 15 date is why traders who run their activity through an S corp or partnership have to move earlier than the April crowd.

Here is how the timing lines up:

Taxpayer type	Election due for 2025 tax year	Extension helps?
Individual (calendar year)	Unextended due date of 2024 Form 1040 (April 2025)	No
Calendar-year S corp or partnership	Unextended due date of 2024 entity return (March 15, 2025)	No
New entity formed in 2025	Within 2 months and 15 days of the start of the tax year	N/A

A newly formed trading entity does not have a prior-year return to attach to, so it makes an internal election under Rev. Proc. 99-17 by placing a statement in its books and records within 2 months and 15 days of the beginning of the tax year for which it is effective.

Step 4: Make the election the way the procedure requires

For an existing taxpayer, the election is a two-part process under Rev. Proc. 99-17.

1. File the election statement on time. Attach a statement to your prior-year return, or to a properly filed extension request (Form 4868 for individuals, Form 7004 for entities), filed by the unextended due date. The statement identifies the election under §475(f), the first tax year it is effective, and the trade or business to which it applies.
2. File Form 3115 the following year. The change to mark-to-market accounting is a change in accounting method. In the year the election first takes effect, you attach Form 3115, Application for Change in Accounting Method, to that year's return and report any §481(a) adjustment for the difference between your old method and the new one.

Skip either part and the position is exposed. The election statement is what meets the deadline; Form 3115 is what perfects the method change.

Step 5: Work through a real example

Consider a former software engineer, single, who left a salaried job in late 2023 to day-trade equities and options full time. In 2024 he traded on roughly 240 of the year's trading days, several hundred round trips a month, holding periods measured in hours. That is a defensible trader profile. He had TTS and deducted his platform fees, data subscriptions, and home-office use on Schedule C.

What he did not do was make the §475(f) election. In 2024 he netted a $210,000 loss. Without mark-to-market, those are capital losses. He could offset his capital gains, then deduct $3,000 against other income under §1211(b), and carry forward roughly $207,000 at $3,000 a year. To use it up he would need to sit on that carryforward for decades or generate future capital gains to absorb it.

Had he filed the one-paragraph election statement by the April 2024 deadline (for the 2024 tax year), the same $210,000 would have been an ordinary loss on Form 4797, fully deductible against his other income and, to the extent it created a net operating loss, carried forward under §172 with no $3,000 cap. The cost of the miss was not the trading. It was the paragraph he did not attach in time. For 2025 he made the election by the April 2025 deadline and filed Form 3115 with his 2025 return.

Step 6: Understand what you cannot easily undo

The §475(f) election is not one you toggle year to year. Once made, it applies to that year and all later years until you get IRS consent to revoke it, again through an accounting-method change under Form 3115 following the procedures the IRS has issued for §475 revocations. Plan the election around your actual strategy, not a single bad year, because you are choosing a method you will live with.

Two practical limits worth stating:

• The election covers your trading business. Positions you genuinely hold for investment, segregated and identified as such, can stay on capital treatment. Keep those accounts clearly separate.
• Making the election does not by itself establish that you are a trader. If the underlying trader status fails on exam, the election riding on top of it fails too.

Sources

• IRC §475(f) (mark-to-market election for traders)
• IRC §1211(b) (capital loss limitation)
• IRC §1091 (wash sale rules)
• IRC §172 (net operating losses)
• IRC §481(a) (adjustments from a change in accounting method)
• Rev. Proc. 99-17 (procedures for making the §475(f) election)
• Form 4797, Sales of Business Property
• Form 3115, Application for Change in Accounting Method
• Form 4868 (individual extension) and Form 7004 (entity extension)
• Schedule C and Schedule D, Form 1040