This page gives you a clear, human explanation of how to complete Form 6781, what the IRS expects, and how to keep your files clean so reviews move faster. You will see step by step instructions, quick examples you can reuse in workpapers, and a short FAQ your team can copy into client emails.
Note on currency of rules, the IRS “About Form 6781” page shows no recent developments as of June 21, 2025, so the long standing mark to market rule and the 60,40 character split remain in place. We cite primary IRS sources throughout so you can confirm lines and elections while you work.
Key takeaways
- You report Section 1256 contracts on Form 6781, with year‑end mark to market and a mandatory 60 percent long term, 40 percent short term split that applies regardless of holding period.
- Totals flow to Schedule D, you include Form 6781 with your Form 1040, and you use your broker’s Form 1099 B data, including the aggregate Section 1256 amount, to populate Part I.
- Part II covers straddles and related deferrals, and Part III captures year‑end unrecognized gains when you recognize a loss on a position in a straddle.
- A net Section 1256 contracts loss can be carried back three years, only against prior Section 1256 gains, by making the election on Form 6781 and filing Form 1045 or an amended return, subject to limits.
- As of November 20, 2025, the IRS has not posted new mechanics for Form 6781, so continue to use the current three part structure, your mark to market worksheet, and your usual Schedule D mapping.
Quick orientation The IRS defines Section 1256 contracts to include regulated futures, nonequity options, certain foreign currency contracts, dealer equity options, and dealer securities futures. All open positions are treated as sold at fair market value on the last business day of the tax year, then split 60,40 on Form 6781.
Who this is for
- You prepare or review returns that include index options, futures, or other Section 1256 instruments.
- You need clean workpapers that a reviewer or partner can sign off quickly.
- You want to confirm carryback, straddle, and mixed straddle election points with current IRS language.
A quick note about Accountably, because this lives on our site, if your firm is buried in 6781 mark to market tie outs and straddle documentation each spring, our U.S. led teams can standardize workpapers, naming, and review steps so you spend less time in loops and more time on planning calls. We only mention this where it helps you ship work on time.
What Form 6781 covers
Form 6781 captures two buckets, Section 1256 contracts under the mark to market rules and straddles under section 1092. The “About Form 6781” page confirms that scope, and Publication 550 explains how amounts feed Schedule D after you compute the 60,40 character split.
Why firms hit friction on 6781
- The 1099 B shows an aggregate Section 1256 amount, your team must still reconcile to daily statements and open positions at year end.
- Straddle deferrals and mixed straddle elections live partly in Pub 550 and partly in regulations, so reviewers need clear notes and cites.
- Carryback rules use a separate form and cannot create an NOL, so reviewers must check prior year 1256 gains and attach the right schedules.
What you report, how the 60,40 split works, and where it lands on the return
What counts as a Section 1256 contract
For Form 6781, think in five buckets you can label in your spreadsheet, regulated futures contracts, nonequity options such as broad based index options, foreign currency contracts traded on a qualified board, dealer equity options, and dealer securities futures. The IRS lists these on the Form 6781 page and in Pub 550.
- Your end of year rule, every open Section 1256 contract is treated as sold at fair market value on the last business day of the tax year. That deemed gain or loss is included on Form 6781.
The mandatory 60,40 character split
Once you net all Section 1256 results in Part I, you divide the net result into 60 percent long term and 40 percent short term, regardless of when you opened the trade. This split is statutory and continues to apply for 2025 filing, which the IRS confirms by showing no new developments for the form as of June 21, 2025.
- After you compute the split, the long term and short term portions flow to Schedule D on their respective lines. Pub 550’s reporting section explains this mapping.
A quick numbers walkthrough
Say your client traded index options and futures during the year and your net Section 1256 gain is 12,500. Your Form 6781 Part I shows the net, then you split it, 7,500 long term and 5,000 short term. Those amounts move to Schedule D, long term on line 11 and short term on line 4 for individuals, consistent with Pub 550’s “How to report” guidance.
Now suppose an open futures position shows an unrealized gain of 4,200 on December 31. You include that mark in the same Part I total for the year, then make a basis adjustment going into the next year so you do not double count it when the position actually closes. Pub 550 outlines this year end recognition, then later basis adjustment.
Hedging exception you should not miss
If a position was properly identified as a hedge on the day you entered it, the mark to market rule for Section 1256 does not apply and ordinary treatment can apply instead. Make sure your file includes timely identification, otherwise you cannot claim hedge treatment later. Pub 550 explains the identification timing and the ordinary income result.
Where the broker’s 1099 B fits
Most brokers place the aggregate Section 1256 profit or loss on Form 1099 B, historically in box 11. You start Part I with that total and then incorporate your year end marks and adjustments as needed, then map the 60,40 split to Schedule D. Keep the year end statement and any pricing files in your workpapers. Pub 550 directs you to use the broker 1099 B and to include a copy of Form 6781 with the return.
Table, the three parts of Form 6781
| Section | Purpose | What you include |
| Part I | Section 1256 contracts | Year end marks and closed trades, then 60,40 character split. |
| Part II | Straddles | Loss deferrals and gains for identified straddles, plus any mixed straddle entries when elections do not move items to Part I. |
| Part III | Unrecognized year end gains | Used when you recognize a loss on a straddle position and must report offsetting unrecognized gains at year end. |
Pro tip for reviewers Do not rush the Schedule D tie out. After you post the 60,40 amounts, scan the return for any duplicate reporting from Form 8949 imports. That double count shows up more often than you would expect, and Pub 550 is your anchor for the correct mapping.
Step by step, completing Parts I, II, and III cleanly
Part I, get the net result and split it 60,40
- Start with the broker’s aggregate Section 1256 amount, then add or subtract your year end mark entries for open 1256 positions. Pub 550’s “How to report” section ties the broker report to Form 6781.
- Net all gains and losses from Section 1256 contracts for the year.
- Apply the 60 percent long term and 40 percent short term character split to the net. Post the long term piece to Schedule D long term, and the short term piece to Schedule D short term.
Documentation you should save with the return, the year end pricing source for each open contract, the calculation of fair market value, your mark worksheet, and any reconciling items to the 1099 B, for example late corrected statements.
Part II, straddles under section 1092
If your client held offsetting positions that substantially reduce risk of loss, a straddle exists. Loss recognition on one leg can be deferred or reduced by unrecognized gains in the offsetting leg. Pub 550 explains how you report these items in Part II, along with the coordination rules that prevent double benefits.
- Section A is typically where you reflect disallowed or deferred losses.
- Section B is where gains are reported for the straddle context.
- Keep a simple identification note, the date you determined the straddle exists and which positions offset which.
Part III, year end unrecognized gains
When you recognize a loss on one position in a straddle and there are unrecognized gains on offsetting positions at year end, you report the unrecognized gains in Part III. This prevents you from taking the loss without also recognizing the related gain still embedded in the open leg. Pub 550 outlines when and how these amounts are taken into account.
Quality control checklist for 6781 workpapers
- One page summary with total Section 1256 net, the 60,40 split, and Schedule D mapping.
- Mark to market worksheet for each open position at year end, include source pricing and the last business day date.
- Straddle memo that lists legs, dates, and any disallowed amounts or carryforwards.
- Copy of broker 1099 B and any corrected statements.
Example, a clean mark to market entry
- On December 31, a broad index futures contract is worth 131,000 while basis is 126,500, your unrealized gain is 4,500.
- You record the mark to market gain in Part I and include it in the net.
- Next year when you close the contract for 130,000, you record a 1,000 loss, because last year’s mark raised your basis. Pub 550 describes this year end recognition and later basis adjustment.
Review tip If the client insists a position was a hedge, look for same day identification. Without that, hedge treatment generally fails and the position belongs in Part I with the 60,40 split. Pub 550 sets that timing test.
Mixed straddles, elections, and the 3‑year carryback for net 1256 losses
Mixed straddles, three elections that change where you report
A mixed straddle combines a Section 1256 contract with a non‑1256 position, for example a regulated futures contract paired with a forward or an equity option. Pub 550 describes three elections that change reporting and character.
- Election A, elect out of mark to market for the 1256 leg of the mixed straddle, then apply the general straddle rules to all legs. Check box A on Form 6781 if you made this election.
- Election B, straddle by straddle identification, where you offset gains and losses for each identified straddle. Check box B to identify this method and follow the Pub 550 rules for character.
- Election C, mixed straddle account, where you compute periodic net amounts for a designated class of activities. Character depends on which side produces the net. Pub 550 walks through the daily account approach.
Practical tip, add a small table to your workpapers listing which election applies, when it was made, and where each item lands on Form 6781. This saves back and forth later.
The 3‑year carryback for a net Section 1256 contracts loss
If the year ends with a net Section 1256 loss, an individual can elect to carry that loss back three years, but only to the extent of prior Section 1256 gains, and the carryback cannot create or increase an NOL. The IRS tells you to make the election on Form 6781, then file Form 1045 or an amended return for the carryback year with amended Form 6781 and Schedule D attached. The Instructions for Form 1045 spell out these steps and limits, and the Internal Revenue Manual reiterates the three year window.
Simple workflow you can copy into your file:
- Check the election box on Form 6781 for the loss year.
- Pull prior year returns and list Section 1256 gains by year, oldest first.
- Prepare Form 1045 or 1040 X for the earliest year with gains, attach the amended Form 6781 and amended Schedule D, then move forward year by year until the loss is absorbed, subject to the limits.
Disclosure for clients, carrybacks can interact with other items in the prior year. The Instructions for Form 1045 discuss cross effects, for example the treatment of other credits in carryback years. Keep your allocation schedules in the file.
Common review traps with straddles
- Loss deferrals missed because the open leg still had unrecognized gains at year end. Pub 550 has examples that match this pattern.
- Mixing hedge identification and straddle presentation. Confirm the hedge identification date before you change treatment.
- Moving mixed straddle items to the wrong part of the form after an election. Pub 550 explains where each election sends the net.
If your team handles many trader returns in a short window, consider a short internal SOP, a one page carryback flow, a mixed straddle election checklist, and a standard naming convention for 6781 workpapers. If you need help producing and enforcing those SOPs, Accountably can supply trained teams that work inside your stack and templates, which keeps reviewers out of ping pong loops.
Practical examples, documentation, and a ready to use checklist
Example A, a year end mark and a next year close
- Client opens two E‑mini futures in August, total basis 98,000.
- On December 31, settlement shows fair value 103,600, unrealized gain 5,600.
- You include 5,600 in Part I, split 3,360 long term and 2,240 short term, and map to Schedule D.
- In February, client closes both for 102,400, real world proceeds are lower than year end, so the 2025 return will show a 1,200 loss after the prior year basis adjustment. Pub 550 describes this sequence.
Example B, a simple straddle with loss deferral
- Client buys a broad index call and writes a related call that offsets most risk.
- In November the purchased call expires worthless, apparent loss 2,800.
- At year end, the written call has 2,000 of unrecognized gain.
- Part II disallows 2,000 of the loss for the year, you carry it forward and track the remainder until the offsetting position is closed. Pub 550 covers this loss coordination.
Documentation checklist you can paste into your template
- Broker 1099 B with the aggregate Section 1256 line circled, plus any corrected forms.
- Daily or month end statements and a one page reconciliation to your Form 6781 Part I total.
- Year end pricing source and a screenshot or export, date stamped for the last business day of the tax year.
- Straddle memo with positions, dates, identification notes, and any deferred losses or unrecognized gains.
- If carrying back a net 1256 loss, the election on Form 6781 for the loss year, Form 1045 or 1040 X packages for each carryback year, and amended Schedules D.
Software notes
Major tax suites can generate Form 6781, but many still require manual entry of the 1099 B aggregate and your year end marks. Intuit’s ProSeries and related products provide specific steps for opening and populating Form 6781 inside the return. Use vendor docs to train juniors on where to enter the total and where to find the 60,40 split outputs that feed Schedule D.
Time saver Build a simple import sheet, columns for contract type, open date, close date, proceeds, cost, year end FMV, straddle yes,no, and election flags. When a client brings heavy trading, that single sheet drives the entire form and reduces review time.
FAQs, deadlines, compliance, and next steps
What is Form 6781 used for
You use it to report gains and losses from Section 1256 contracts, including year end mark to market, and to report straddles under section 1092. Results split 60,40 then flow to Schedule D. The IRS confirms this scope on its Form 6781 page.
Where do I start Part I if I have a broker 1099‑B
Start with the aggregate Section 1256 amount from the 1099 B, historically box 11, then add your year end mark to market for open 1256 positions. Net the result, split 60,40, and map to Schedule D. Pub 550 explains the broker to Form 6781 connection and the mapping.
Do the rules change for hedges
Yes. Properly identified hedging transactions are not subject to the Section 1256 mark to market rule and usually receive ordinary treatment. Identification must be made on the day you enter the hedge. Pub 550 provides the specifics.
Can I carry back a net 1256 loss
If you are an individual, you may elect to carry it back three years, but only to offset prior Section 1256 gains, and you cannot create or increase an NOL. Make the election on Form 6781 for the loss year, then file Form 1045 or 1040 X with amended Form 6781 and Schedule D for each carryback year. See the Instructions for Form 1045 and the Internal Revenue Manual on carrybacks.
Are there any 2025 changes to Form 6781 mechanics
As of June 21, 2025, the IRS shows no recent developments on the Form 6781 page, so continue with the three part structure, mark to market at year end, and the 60,40 split. Always check the IRS page for any late season updates.
Final checks before you file
- Confirm the 60,40 split and the Schedule D tie out.
- Confirm straddle deferrals and any Part III entries if you recognized a loss while an offsetting leg had unrecognized gains.
- If carrying back a net 1256 loss, attach the right amended schedules for each year and respect the limits.
Compliance and sourcing This article reflects IRS pages reviewed as of November 20, 2025. Key sources include the IRS “About Form 6781” page, Publication 550, the Instructions for Form 1045, and the Internal Revenue Manual section on carrybacks.
How Accountably can help, only if you need it
If you need extra hands during peak season, Accountably integrates trained offshore teams into your workflow, inside your software, with standardized 6781 workpapers, naming, and review steps. That means clean marks, faster reviews, and fewer back and forth emails. If that would help your team, reach out. If not, copy the checklists above into your SOP and you will still move faster.
Disclosure
This guide was prepared by Accountably’s U.S. led tax team with assistance from automation, then reviewed by a CPA for accuracy as of November 20, 2025. Always confirm current IRS instructions before filing.