Form 8933 Schedule D – Recapture Certification Guide

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On a 45Q engagement, the easy mistake is reaching for Schedule D out of habit and building it for a year with no recapture event. It is a recapture certification, not a routine annual attachment. You complete it only when the math on Part II says a recapture event actually occurred, where line 5 (line 3 minus line 1) comes out greater than zero under Regulations section 1.45Q-5(d).

When that happens, Schedule D (Form 8933) (Rev. December 2025, Catalog No. 94875N) works from your prior-year storage records outward, with a lookback limited to the current tax year plus the three previous tax years. The recaptured credit then flows to Form 8933, Part III, line 10, and you run a separate Part III for each carbon oxide supplier in that window.

Key Takeaways

Form 8933 Schedule D is the Recapture Certification for the Section 45Q carbon oxide sequestration credit – you complete it only when a recapture event occurs (Part II, line 5 greater than zero) and attach it to Form 8933.
Schedule D is not filed per facility; when a recapture event occurs you complete a separate Part III for each carbon oxide supplier from the three-year lookback and file the schedule within the same Form 8933 package.
A recapture event occurs only when the metric tons that will eventually migrate to the atmosphere (Part II, line 3) exceed the metric tons securely stored during the year (Part II, line 1); leakage alone does not trigger it.
Supporting attachments depend on how sequestration was determined: an MRV plan under 40 CFR Part 98 subpart RR (Part I, line 11), or ISO 27916 documentation plus a qualified independent engineer or geologist certification (Part I, line 12).
The recapture lookback on Schedule D is limited to the current tax year plus the three previous tax years; carbon oxide stored before that window is not subject to recapture and is reported on Part II, line 9E.
Recaptured credit flows to Form 8933, Part III, line 10 – to the EOR owner when the supplier made the Section 45Q election to transfer the credit, otherwise to the supplier on its own return.

What Form 8933 Schedule D Is

Form 8933 is the IRS return for the Section 45Q carbon oxide sequestration credit, and it carries several schedules. Schedule D is the Recapture Certification: it documents the geological disposal site or EOR project, the carbon oxide subject to recapture when stored CO2 leaks, and how the recaptured credit is allocated among owners and suppliers. It attaches to Form 8933 and is not a standalone filing.

Schedule D does not feed the original credit calculation; it is completed only when a recapture event reverses part of a previously claimed Section 45Q credit. The IRS instructions are explicit: do not complete the schedule if a recapture event did not occur. In an audit context, Schedule D documents whether stored carbon oxide has leaked and triggered recapture – it is the certification that quantifies the give-back and routes it to Form 8933, Part III, line 10.

A completed Schedule D includes owner information for the current and three previous tax years (Part I), the geological disposal site or EOR project details, the carbon oxide subject to recapture (Part II), and a per-supplier recapture determination (Part III). When carbon oxide came from more than one supplier, complete a separate Part III for each supplier from the three-year lookback.

Part I: Owner and Disposal Site Information

Part I identifies who owned the project and where it sits. Section 1 collects, for the current tax year and each of the three previous tax years, every owner’s name, EIN, address, and operating interest percentage. The form provides four owner slots (A through D) across four year columns (current plus 1st, 2nd, and 3rd previous tax years), which is why the recapture analysis is inherently a multi-year, multi-owner exercise.

Section 2 captures the project itself. On line 2 you check whether the project is a geological disposal site or an EOR project. Line 3 records the project name and its location (county and state). For an EOR project, lines 4a and 4b take the operator’s name and EIN. Line 6a records the IRS-issued registration number(s) for the disposal site, and line 6b takes the EPA e-GGRT ID number(s) if available. Line 7 records the month and year (MM/YYYY) on which injection of captured carbon oxide began.

Lines 8 through 12 handle the certification trail. If the EOR project was previously certified under Section 43, line 8a takes the certified project’s name; line 8b takes the date (MM/YYYY) of the petroleum engineer’s certification. If it was not previously certified under Section 43, line 9 requires a valid petroleum engineer’s certification to be attached. Line 10 asks whether the EOR project is an enhanced natural gas recovery project.

Sequestration Determination: MRV Plan or ISO 27916

How the sequestered carbon oxide was measured drives which attachments Schedule D requires, and both routes live in Part I.

40 CFR Part 98 subpart RR – if the amount of sequestered carbon oxide was determined under EPA’s Greenhouse Gas Reporting Program subpart RR, line 11 requires you to attach a copy of the approved Monitoring, Reporting, and Verification (MRV) plan, or provide the URL of it on the EPA’s website.
ISO 27916 – if the amount was determined under ISO 27916, line 12 requires two attachments: the ISO 27916 documentation for the tax year, and a certification by a qualified independent engineer or geologist. A common slip is attaching only the documentation and forgetting the engineer or geologist certification.

From my side of the desk, this is the part of the file I confirm first. The recapture math means nothing if the underlying measurement basis is not documented the way the schedule expects, so the MRV plan or the ISO 27916 package and its certification have to be in hand before the schedule comes together.

Part II: Determining the Carbon Oxide Subject to Recapture

Part II is where the recapture test actually runs. Line 1 lists the total metric tons of qualified carbon oxide securely stored in the disposal site or EOR project during the year. Line 2 lists the metric tons the owner, operator, or a regulatory agency determined have leaked from the containment area during the year or previous tax years if not previously accounted for. Line 3 narrows that to the leaked tons that will eventually migrate to the atmosphere.

The trigger – line 5 is line 3 minus line 1. If it is greater than zero, a recapture event has occurred under Regulations section 1.45Q-5(d), and you complete the rest of Part II. If it is zero or negative, you do not complete the schedule at all.
Supporting statements – if line 3 is less than line 2, line 4 requires a statement explaining how you determined the difference will not eventually migrate. Line 6 requires a statement describing the cause of the leakage, and line 7 asks which regulatory agencies were made aware of it.
Prior-year schedules – line 8 requires you to attach Schedule B (Form 8933) or Schedule C (Form 8933) for the disposal site for each of the previous three tax years.

Line 9 then builds the table of stored carbon oxide subject to recapture across the three prior years (rows A, B, C) and allocates it among owners. Line 9E carves out the metric tons not subject to recapture because the lookback is limited to three tax years, by subtracting Part II line 5 from line 9D, column (c).

The Recapture Lookback Window

The single most important number on this schedule is how far back recapture reaches. The lookback on Schedule D is limited to the current tax year plus the three previous tax years. Carbon oxide stored before that window is not subject to recapture and is carved out on Part II, line 9E, which subtracts Part II line 5 from line 9D, column (c).

A recapture event occurs only when the qualified carbon oxide that will eventually migrate to the atmosphere (Part II, line 3) exceeds the metric tons securely stored during the year (Part II, line 1). Leakage on its own does not trigger recapture – the line 3 versus line 1 comparison does. That is why I treat any leakage finding as a question to be tested, not an automatic give-back.

Filed Only on a Recapture Event

Schedule D is filed only in a year in which a recapture event actually occurs (Part II, line 5 greater than zero), not routinely to confirm that previously sequestered carbon oxide remains in place. The Instructions for Form 8933 state plainly that you do not complete the schedule if a recapture event did not occur. For sequestration determined under 40 CFR Part 98 subpart RR, the approved MRV plan attaches at Part I, line 11; the schedule itself, however, comes off the shelf only when the recapture math says so.

Part III: Per-Supplier Recapture Determination

Part III sorts out who actually bears the recapture when carbon oxide came from a supplier. Section 1 identifies you, the owner of the EOR project (name, EIN, address). Section 2 then covers suppliers who supplied carbon oxide during any of the three previous tax years – the same three-year lookback used in Part II. The form is explicit that you complete a separate Part III for each supplier.

For each supplier, the line 8 table runs the prior three years (rows A, B, C) and computes two parallel amounts: the credit the EOR owner must recapture (column f metric tons multiplied by the column e rate, totaled on line 8E) and the credit the supplier must recapture (column h metric tons multiplied by the column e rate, totaled on line 8G).

Who Recaptures Depends on the Supplier’s Election

This is the detail that trips people up. When a supplier elected to allow the EOR project owner to claim the Section 45Q credit, the EOR owner adds the line 8E amount to its own Form 8933, Part III, line 10. When the supplier did not make that election, the supplier itself must add the line 8G amount to its Form 8933, Part III, line 10. The recapture does not automatically fall on the EOR owner – it follows whoever claimed the original credit.

How to Complete Schedule D

Schedule D is organized into three parts – Part I (owner and geological disposal site or EOR project information), Part II (determination of recaptured qualified carbon oxide), and Part III (per-supplier recapture determination). Here is how I work through each section:

Part I: Owner and Site Identification

Enter the owner information for the disposal site or EOR project in Part I, Section 1, across the current and three previous tax years, and the project name and location (county and state) on line 3. The EOR project operator’s EIN appears on line 4b. Record the IRS-issued registration number(s) on line 6a, the EPA e-GGRT ID(s) on line 6b if available, and the injection start date (MM/YYYY) on line 7.

Part II: Run the Recapture Test

Report the total metric tons of qualified carbon oxide securely stored in the disposal site or EOR project during the year on Part II, line 1, drawn from your monitoring data. Enter the metric tons leaked on line 2 and the tons that will eventually migrate to the atmosphere on line 3. Compute line 5 by subtracting line 1 from line 3. Schedule D does not compute the original credit – line 5 determines the amount subject to recapture, and if it is not greater than zero there is no recapture event and no schedule to file.

Carry the Attachments and Statements

If line 3 is less than line 2, attach the line 4 statement. Attach the line 6 leakage-cause statement and identify the regulatory agencies on line 7. Attach Schedule B or Schedule C (Form 8933) for each of the previous three tax years on line 8, and carry prior-year stored carbon oxide from Schedule C (Form 8933), line 20, column (m) into Part II, line 9, column (b).

Part III: One Per Supplier

Complete a separate Part III for each carbon oxide supplier from the three-year lookback, and route the recaptured amounts to Form 8933, Part III, line 10 – the line 8E (column g) totals to the EOR owner, the line 8G (column i) totals to the supplier. The number of Part III copies follows the number of suppliers, not the number of owners.

Deadlines and Filing Requirements

Taxpayer Type	Original Due Date	Extended Due Date
C Corporations (calendar year)	April 15	October 15
Partnerships and S Corps (calendar year)	March 15	September 15
Individuals	April 15	October 15
Tax-exempt organizations (Form 990-T)	15th day of 5th month after year-end	15th day of 11th month after year-end

Schedule D is filed as part of the Form 8933 package with the taxpayer’s annual income tax return, but only for a tax year in which a recapture event has actually occurred; the IRS instructions direct you not to complete the schedule unless Part II line 5 (line 3 minus line 1) is greater than zero. There is no separate filing or extension for Schedule D alone. Where they apply, the MRV plan (Part I, line 11) or the ISO 27916 documentation and the qualified independent engineer or geologist certification (Part I, line 12) should be assembled before the return is filed so the schedule has its supporting trail in hand.

Recapture Rules

The recapture mechanism is one of the more unusual aspects of this credit. If carbon oxide that was previously stored is later determined to have leaked, the credit attributable to those escaped metric tons is recaptured in the year the recapture event is confirmed – but only where the event is actually triggered on Part II line 5, meaning the qualified carbon oxide that will eventually migrate to the atmosphere (line 3) exceeds the amount securely stored that year (line 1). The governing rule is Regulations section 1.45Q-5(d).

Recapture is computed by multiplying the escaped metric tons by the credit rate that applied to those tons (Part III, column f or column h times column e). The recapture amount is added back through Form 8933, Part III, line 10 in the year it is confirmed. Who bears it depends on the supplier’s Section 45Q election: if the supplier elected to let the EOR project owner claim the credit, the owner recaptures on its own Form 8933, Part III, line 10; otherwise the supplier recaptures on its own return.

From my side of the desk, the recapture exposure is real but bounded. The lookback reaches back only three tax years, the test is a clean line 3 versus line 1 comparison, and the give-back routes to a single line. But the engagement letter still needs to reflect that the tail exists, and the client should understand that a leakage finding can reopen prior-year credits within that window.

Common Mistakes That Slow Things Down

A recurring pattern shows up when a credit that ran clean for years suddenly hits a leakage question: the team reaches for Schedule D out of habit and gets the framing wrong. Here are the errors my team catches most often on this schedule.

1. Filing Schedule D in a year with no recapture event. Schedule D is the Recapture Certification, not an annual attachment to Form 8933. You complete it only when Part II line 5 (line 3 minus line 1) is greater than zero, which is the test for a recapture event under Regulations section 1.45Q-5(d). Fix: Run the Part II line 1 versus line 3 comparison before you touch the schedule; if line 5 is zero or negative, the schedule stays out of the filing package.

2. Treating any leakage as a recapture event. Leakage alone does not trigger recapture. A recapture event exists only when the metric tons that will eventually migrate to the atmosphere on Part II line 3 exceed the metric tons securely stored during the year on Part II line 1. Fix: Document the line 1 and line 3 figures from your monitoring data first, and if line 3 is less than line 2, attach the Part II line 4 statement explaining why the difference will not migrate.

3. Reaching past the three-year lookback. The recapture base is limited to the current tax year plus the three previous tax years. Carbon oxide stored earlier than that window is not subject to recapture and belongs on Part II line 9E, which subtracts Part II line 5 from line 9D, column (c). Fix: Pull Schedule C (Form 8933), line 20, column (m) for each of the three prior years to populate Part II line 9, and exclude anything older than the lookback.

4. Attaching only the ISO 27916 documentation. When sequestration is determined under ISO 27916, two attachments are required, not one. The tax-year ISO 27916 documentation and a certification by a qualified independent engineer or geologist both have to be in the package on Part I line 12. Fix: Add a check to your prep SOP so the engineer or geologist certification is collected alongside the ISO documentation, the same way Part I line 11 expects the MRV plan under 40 CFR Part 98 subpart RR.

5. Assuming the EOR project owner always bears the recapture. Who recaptures depends on the supplier's election. If a supplier elected to let the EOR owner claim the Section 45Q credit, the EOR owner recaptures on its own Form 8933, Part III, line 10; if the supplier did not, the supplier recaptures on its own return instead. Fix: Complete a separate Part III for each supplier and confirm election status before routing column (g) and column (i) totals to the right party.

6. Sending Parts I and II only to current-year owners. The schedule requires copies for everyone who held the disposal site or EOR project during the current year and the three previous tax years, not just today's owners, per Part II line 13. Fix: Build the distribution list from Part I, Section 1, which already tracks owners across all four year columns, and send copies of Parts I and II to each one.

Practical Checklists You Can Reuse

These are copy-paste ready for your firm SOPs. Lift them into your workpaper template so the recapture test and the attachment trail run the same way on every engagement.

Recapture event test (run this first)

Confirm the project type on Part I line 2: geological disposal site or EOR project.
Pull metric tons securely stored during the year for Part II line 1 from continuous monitoring data.
Enter metric tons leaked during the year or prior years on Part II line 2.
Enter metric tons that will eventually migrate to the atmosphere on Part II line 3.
Compute Part II line 5 by subtracting line 1 from line 3.
If line 5 is zero or negative, stop; no recapture event occurred and Schedule D is not filed.
If line 3 is less than line 2, attach the Part II line 4 statement explaining why the difference will not migrate.

Schedule D build packet

Record the IRS-issued registration number(s) on Part I line 6a and EPA e-GGRT ID(s) on line 6b if available.
Enter the injection start date (MM/YYYY) on Part I line 7.
Attach the petroleum engineer's certification on Part I line 9 if the EOR project was not previously certified under Section 43.
Attach the approved MRV plan, or its EPA URL, for sequestration under 40 CFR Part 98 subpart RR on Part I line 11.
For ISO 27916 sequestration, attach both the ISO documentation and a qualified independent engineer or geologist certification on Part I line 12.
Attach Schedule B or Schedule C (Form 8933) for each of the three previous tax years for Part II line 8.
Attach the leakage-cause statement for Part II line 6 and identify regulatory agencies notified on Part II line 7.

Owner and supplier routing

Carry prior-year stored carbon oxide from Schedule C (Form 8933), line 20, column (m) into Part II line 9, column (b).
Allocate the line 9 column (c) amount across owners; check the Part II line 12 box and attach a statement if the allocation is not pro rata.
Provide copies of Parts I and II to every owner during the current and three previous tax years per Part II line 13.
Complete a separate Part III for each supplier from the three-year lookback.
Route Part III line 8E totals to Form 8933, Part III, line 10 for the EOR owner.
Route Part III line 8G totals to the supplier's own Form 8933, Part III, line 10.

Keep Schedule D (Form 8933) Season From Stalling

Schedule D rarely lands on a calendar. It surfaces when monitoring data flags a leakage question, and by then you are reconstructing metric ton figures across four tax years and, in many cases, several owners and suppliers. The December 2025 revision runs four pages across three parts, and each part pulls from a different prior-year record (per the Instructions for Form 8933).

That reconstruction work is where engagements stall. The fix is to treat the recapture certification as a documentation problem you solve before the event, not a fire drill you run after it. When the prior-year schedules and owner records are already structured, completing Schedule D becomes a transcription task instead of an archaeology project.

Keep Schedule C (Form 8933), line 20, column (m) totals for the last three years in a standing workpaper so Part II line 9 populates without a year-end scramble.
Maintain an owner and operating-interest register tied to Part I, Section 1, so the four-year copy requirement on Part II line 13 is ready on demand.
Track each supplier's Section 45Q election status year by year so Part III routes the column (g) and column (i) totals to the correct Form 8933, Part III, line 10.
Store the MRV plan, ISO 27916 documentation, and engineer or geologist certifications as you go, not when a recapture event forces Part I lines 11 and 12.

This is the kind of structured, multi-year recordkeeping our tax execution teams maintain inside your workflow, so when a recapture event does surface, the supporting trail is already built and the schedule comes together on time.

FAQs

What does Form 8933 Schedule D report?

Schedule D (Form 8933) is the Recapture Certification for the Section 45Q carbon oxide sequestration credit. It is completed only when a recapture event occurs, meaning the metric tons of qualified carbon oxide that will eventually migrate to the atmosphere (Part II, line 3) exceed the metric tons securely stored during the year (Part II, line 1) so Part II, line 5 is greater than zero. It captures owner and geological disposal site or EOR project information, the carbon oxide subject to recapture, and the per-supplier recapture determination, with recaptured credit flowing to Form 8933, Part III, line 10.

What supporting documentation does Schedule D require?

The metric tons reported on Schedule D are backed by the attachments the schedule itself calls for. If sequestration was determined under 40 CFR Part 98 subpart RR, attach the approved Monitoring, Reporting, and Verification (MRV) plan or provide its EPA URL on Part I, line 11. If it was determined under ISO 27916, attach both the ISO 27916 documentation for the tax year and a certification by a qualified independent engineer or geologist on Part I, line 12. An EOR project not previously certified under Section 43 must attach a valid petroleum engineer’s certification on Part I, line 9.

Can one taxpayer have multiple Schedule D filings?

Schedule D is the Recapture Certification and is completed only for a tax year in which a recapture event occurred (Part II, line 5 greater than zero); the IRS instructions say not to complete it if no recapture event occurred. When it applies, complete a separate Part III for each carbon oxide supplier from the three-year lookback and attach the schedule to the Form 8933 package filed with the taxpayer’s annual income tax return.

How does Schedule D treat an enhanced oil recovery (EOR) project?

On Part I, line 2 you check whether the project is a geological disposal site or an EOR project. For an EOR project, Schedule D asks for the operator’s name and EIN, whether it is an enhanced natural gas recovery project, and the petroleum engineer’s certification details. If the EOR project was previously certified under Section 43, state the certified project’s name; if it was not, attach a valid petroleum engineer’s certification (Part I, line 9). Schedule D is a recapture certification, so this information is reported only in a year when a recapture event has occurred.

What happens if captured CO2 leaks from geological storage?

Leakage triggers recapture only when the qualified carbon oxide that will eventually migrate to the atmosphere (Part II, line 3) exceeds the metric tons securely stored that year (Part II, line 1), and the lookback is limited to the current year plus three previous tax years. The recapture amount is the escaped metric tons multiplied by the credit rate originally applied. Whether the EOR project owner or the carbon oxide supplier bears the recapture depends on the supplier’s Section 45Q election, with the amount flowing to that party’s Form 8933, Part III, line 10.

Does Schedule D need to be filed separately from Schedule C?

Schedule D is the Recapture Certification and attaches to Form 8933, but unlike Schedule C it is completed only for a tax year in which a recapture event occurred (Part II, line 5 greater than zero); the IRS instructions direct you not to complete it if a recapture event did not occur. It is not part of the routine annual credit-claim package and is not required to support the original Section 45Q credit.