Definitions

Applicable electric generating unit. An applicable electric generating unit is the principal electric generating unit for which the equipment is originally planned and designed.

Baseline carbon oxide production. A baseline carbon oxide production means either of the following.

• In the case of an applicable electric generating unit that was originally placed in service more than 1 year prior to the date on which construction of the equipment begins, the average annual carbon oxide production, by mass, from such unit during (i) in the case of an applicable electric generating unit that was originally placed in service more than 1 year prior to the date on which construction of the equipment begins and on or after the date that’s 3 years prior to the date on which construction of such equipment begins, the period beginning on the date such unit was placed in service and ending on the date on which construction of such equipment began; and (ii) in the case of an applicable electric generating unit that was originally placed in service more than 3 years prior to the date on which construction of the equipment begins, the 3 years with the highest annual carbon oxide production during the 12-year period preceding the date on which construction of such equipment began.

• In the case of an applicable electric generating unit that (i) as of the date on which construction of the equipment begins, is not yet placed in service; or (ii) was placed in service during the 1-year period prior to the date on which construction of the equipment begins, the designed annual carbon oxide production, by mass, as determined based on an assumed capacity factor of 60%.

Capacity factor. Capacity factor means the ratio (expressed as a percentage) of the actual electric output from the applicable electric generating unit to the potential electric output from such unit.

Carbon capture equipment. This includes all components of property that are used to capture or process carbon oxide until the carbon oxide is transported for disposal, injection, or utilization. Carbon capture equipment is equipment used for the purpose of (1) separating, purifying, drying, and/or capturing carbon oxide that would otherwise be released into the atmosphere from an industrial facility; (2) removing carbon oxide from the atmosphere via DAC; or (3) compressing or otherwise increasing the pressure of carbon oxide.

All components that make up an independently functioning process train capable of capturing, processing, and preparing carbon oxide for transport will be treated as a single unit of equipment (single process train). See Rev. Rul. 2021-13, 2021-30 I.R.B. 152, available at IRS.gov/irb/2021-30_IRB#REV-RUL-2021-13 .

Direct air capture (DAC) facility. A DAC facility means any facility that uses carbon capture equipment to capture carbon oxide directly from the ambient air. It doesn’t include any facility that captures carbon dioxide (1) that’s deliberately released from naturally occurring subsurface springs, or (2) using natural photosynthesis.

Electricity generating facility. An electricity generating facility is a facility described in section 45Q(d)(2)(A) or (B) and is subject to depreciation under MACRS asset class 49.11 (Electric Utility Hydraulic Production Plant), 49.12 (Electric Utility Nuclear Production Plant), 49.13 (Electric Utility Steam Production Plant), or 49.15 (Electric Utility Combustion Turbine Production Plant).

Facility. Any industrial facility or DAC facility (a) the construction of which begins before January 1, 2033, and the construction of carbon capture equipment begins before that date, or the original planning and design for the facility includes installation of carbon capture equipment; and (b) that captures:

1. In the case of a DAC facility, captures not less than 1,000 metric tons of qualified carbon oxide during the tax year;

2. In the case of an electricity generating facility that (i) captures not less than 18,750 metric tons of qualified carbon oxide during the tax year; and (ii) for any carbon capture equipment for the applicable electric generating unit at such facility, has a capture design capacity of not less than 75% of the baseline carbon oxide production of such unit; or

3. In the case of any other facility, captures not less than 12,500 metric tons of qualified carbon oxide during the tax year.

Instructions for Form 8933 (Rev. 12-2025) 3

Industrial facility. An industrial facility is a facility that produces a carbon oxide stream from a fuel combustion source or fuel cell, a manufacturing process, or a fugitive carbon oxide emission source that, absent capture and disposal, would otherwise be released into the atmosphere as industrial emission of greenhouse gas or lead to such release. An industrial facility doesn’t include a facility that produces carbon dioxide from carbon dioxide production wells at natural carbon dioxide-bearing formations or a naturally occurring subsurface spring. Depending on your election to use the June 2020 Notice of Proposed Rulemaking (NPRM) or the TD, see section 3.02(b) of Notice 2009-83 or Regulations section 1.45Q-2(d)(1) and (d)(2). An industrial source is an emission of carbon oxide from an industrial facility.

A manufacturing process is a process involving the manufacture of products, other than carbon oxide, that are intended to be sold at a profit, or are used for a commercial purpose. All facts and circumstances for the process and products are to be taken into account.

Natural gas. Natural gas means any product (other than crude oil) of an oil or gas well if a deduction for depletion is allowable under section 611 for such product.

Qualified carbon oxide. This is (a) any carbon dioxide captured from an industrial source by equipment originally placed in service before February 9, 2018, which would otherwise be released into the atmosphere as industrial emission of greenhouse gas or lead to such release, and is measured at the source of capture and verified at the point of disposal, injection, or utilization; (b) any carbon dioxide or other carbon oxide that’s captured from an industrial source by equipment originally placed in service on or after February 9, 2018, which would otherwise be released into the atmosphere as industrial emission of greenhouse gas or lead to such release, and is measured at the source of capture and verified at the point of disposal, injection, or utilization; or (c) in the case of a DAC facility, any carbon dioxide that’s captured directly from the ambient air, and is measured at the source of capture and verified at the point of disposal, injection, or utilization.

Qualified carbon oxide includes the initial deposit of captured carbon oxide used as a tertiary injectant. It doesn’t include carbon oxide that’s recaptured, recycled, and re-injected as part of the EOR and natural gas recovery process.

Qualified EOR or natural gas recovery project. An EOR or natural gas recovery project means any project located in the United States involving the application of one or more tertiary recovery methods defined in section 193(b)(3) that can reasonably be expected to result in more than an insignificant increase in the amount of crude oil or natural gas that will ultimately be recovered and for which the first injection of liquids, gases, or other matter begins after 1990.

Secure geological storage. Secure geological storage includes, but isn’t limited to, storage at deep saline formations, oil and gas reservoirs, and unminable coal seams.

If you’re claiming a credit for a facility placed in service before February 9, 2018, the following applies.

• Secure geological storage requires approval by the U.S. Environmental Protection Agency (EPA) of a Monitoring, Reporting, and Verification Plan (MRV Plan) submitted by the operator of the storage facility or tertiary injection project.

• The annual amount of carbon oxide claimed for the credit must be consistent with amounts reported to the EPA under its Greenhouse Gas Reporting Program, subpart RR.

See Sections 6 through 8 of Notice 2009-83, 2009-44 I.R.B. 588, available at IRS.gov/irb/ 2009-44_IRB#NOT-2009-83 for reporting and recordkeeping requirements associated with the limitation on credits available under former section 45Q(a) (as in effect before February 9, 2018) and sections 45Q(a)(1) and (2). Sections 1 through 5 of Notice 2009-83 were obsoleted by REG-112339-19, 85 F.R. 34050-34075. After the end of the calendar year in which the Secretary, in consultation with the Administrator of the EPA, certifies that a total of 75,000,000 metric tons of qualified carbon oxide have been taken into account under former section 45Q(a) (as in effect before February 9, 2018) and sections 45Q(a)(1) and (2), the remaining sections of Notice 2009-83 will be obsoleted. Also, see Notice 2022-38, 2022-39 I.R.B. 239, available at IRS.gov/irb/ 2022-39_IRB#NOT-2022-38 . If you’re claiming a credit for a facility that was placed in service in tax years beginning on or after February 9, 2018, qualified carbon oxide is considered disposed of by you in secure geological storage such that the qualified carbon oxide doesn’t escape into the atmosphere if the qualified carbon oxide is:

• Stored, and not used as a tertiary injectant in an EOR or natural gas recovery project, in compliance with applicable requirements under 40 CFR Part 98 subpart RR;

• Used as a tertiary injectant in an EOR or natural gas recovery project and stored in compliance with applicable requirements under 40 CFR Part 98 subpart RR, or the International Organization for Standardization (ISO) standards endorsed by the American National Standards Institute (ANSI) under CSA/ANSI ISO 27916:19, Carbon dioxide capture, transportation, and geological storage—Carbon dioxide storage using enhanced oil recovery (CO2-EOR); and

• Injected into a well that complies with applicable Underground Injection Control regulations onshore or offshore under submerged lands within the territorial jurisdiction of the United States.

Supplier. For qualified carbon oxide, supplier means the person who captured the qualified carbon oxide, which may differ from the company that sold the qualified carbon oxide or physically delivered the qualified carbon oxide to the owner of the geological disposal site or the utilization facility.

Tertiary injectant. An injectant (other than a hydrocarbon injectant that’s recoverable) that’s used as part of a tertiary recovery method. For more details, see section 193(b).

4 Instructions for Form 8933 (Rev. 12-2025)

United States and U.S. territories. This includes the seabed and subsoil of those submarine areas that are adjacent to the territorial waters of the United States (or a U.S. territory) and over which the United States has exclusive rights, in accordance with international law, for the exploration and exploitation of natural resources.

Utilization of qualified carbon oxide. Utilization of qualified carbon oxide means (1) the fixation of such qualified carbon oxide through photosynthesis or chemosynthesis, such as through the growing of algae or bacteria; (2) the chemical conversion of such qualified carbon oxide to a material or chemical compound in which such qualified carbon oxide is securely stored; or (3) the use of such qualified carbon oxide for any other purpose for which a commercial market exists (with the exception of use as a tertiary injectant in an EOR or natural gas recovery project), as determined by the Secretary of the Treasury or his delegate.