0001628280-26-046014 | 11-K | XBRL Viewer | Occidental Petroleum Corp DE

Plan Interest in Master Trust Accounts

12 Months Ended

Dec. 31, 2025

The Plan participates in the Occidental Petroleum Corporation Defined Contribution Plan Master Trust (DCP Master Trust), which invests in various funds that are available to participants including Target Date Funds, Index Funds, and Active Funds. The Plan also invests in a synthetic GIC fund managed by Invesco (GIC MTIA). The Plan and the Occidental Retirement Plan each own an undivided interest in the DCP Master Trust and the GIC MTIA.

The following table presents the Plan interest in each master trust account (amounts in thousands):


	As of December 31,
	2025		2024
Plan interest in master trust accounts:
DCP Master Trust, at fair value	$	3,136,985	$	2,649,136
GIC MTIA, at contract value	229,665		258,996


Net assets	$	3,366,650	$	2,908,132

The following table presents the fair value of net assets held by the DCP Master Trust, in which the Plan owns an undivided interest (amounts in thousands):


	As of December 31,
	2025				2024
	Master Trust Balances		Plan's Interest in Master Trust Balances		Master Trust Balances		Plan's Interest in Master Trust Balances
Assets of DCP Master Trust:
Assets:
Investments at fair value as determined by quoted market price:
Short-term investment fund	$	793	$	552	$	872	$	608
Common/collective trusts	3,850,692		2,680,569		3,208,851		2,238,728
Common stocks	51,619		35,933		22,797		15,905
Mutual funds	602,866		419,671		564,296		393,694
Total investments	4,505,970		3,136,725		3,796,816		2,648,935
Cash and cash equivalents	—		—		14		10
Receivables:

Accrued investment income	810		564		464		324

Total assets	4,506,780		3,137,289		3,797,294		2,649,269
Liabilities:
Due to broker for securities purchased	436		304		190		133
Total liabilities	436		304		190		133
Net assets of DCP Master Trust	$	4,506,344	$	3,136,985	$	3,797,104	$	2,649,136
Plan’s percentage interest in DCP Master Trust net assets			70%				70%

The following table presents the changes in the net assets of the DCP Master Trust, in which the Plan owns an undivided interest, as stated in the table above (amounts in thousands):


	Year Ended December 31,
	2025		2024
Net appreciation in fair value of investments:
Common/collective trusts	$	613,220	$	449,174
Common stocks	5,362		5,570
Mutual funds	35,215		28,234
Net appreciation	653,797		482,978
Interest and dividends	16,484		14,220
Less investment expenses	(427)		(606)
Investment income	669,854		496,592

Transfers in	581,926		555,260
Transfers out	(542,540)		(382,723)
Changes in net assets	$	709,240	$	669,129

The following tables provide fair value measurement information for the DCP Master Trust, in which the Plan owns an undivided interest as of December 31, 2025 and 2024, as discussed in Note 3 (amounts in thousands):


	Assets at fair value as of December 31, 2025
	Level 1		Total
Common stocks	$	51,619	$	51,619
Mutual funds	602,866		602,866
Total assets in the fair value hierarchy	654,485		654,485

Investments measured at NAV:
Short-term investment fund			793
Common/collective trusts			3,850,692
Assets at fair value	$	654,485	$	4,505,970


	Assets at fair value as of December 31, 2024
	Level 1		Total
Common stocks	$	22,797	$	22,797
Mutual funds	564,296		564,296
Total assets in the fair value hierarchy	587,093		587,093

Investments measured at NAV:
Short-term investment fund			872
Common/collective trusts			3,208,851
Assets at fair value	$	587,093	$	3,796,816

The following table presents the net assets held by the GIC MTIA, in which the Plan owns an undivided interest (amounts in thousands):


	As of December 31,
	2025				2024
	Master Trust Balances		Plan's Interest in Master Trust Balances		Master Trust Balances		Plan's Interest in Master Trust Balances
Assets of GIC MTIA:
Assets:
Investments, at contract value (see Note 4):
Short-term investment fund	$	7,706	$	5,330	$	8,944	$	6,259
Synthetic guaranteed investment contracts:
Common/collective trusts - fixed income funds	323,612		223,829		360,227		252,092
Total investments	331,318		229,159		369,171		258,351
Receivables:

Accrued investment income	838		579		922		645
Total receivables	838		579		922		645
Total assets	332,156		229,738		370,093		258,996
Liabilities:

Accrued expenses	106		73		—		—
Total liabilities	106		73		—		—
Net assets of GIC MTIA	$	332,050	$	229,665	$	370,093	$	258,996
Plan’s percentage interest in GIC MTIA net assets			69%				70%

The following table presents the changes in net assets of the GIC MTIA, in which the Plan owns an undivided interest, as stated in the table above (amounts in thousands):


	Year ended December 31,
	2025		2024
Interest Income	$	10,394	$	11,581
Less investment expenses	(438)		(386)
Total investment income	9,956		11,195

Transfers in	54,082		39,934
Transfers out	(102,081)		(100,375)
Changes in net assets	$	(38,043)	$	(49,246)

Oxy Stock Fund - Net Assets (Details) - EBP 001 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Net assets:
Interest and dividends	$ 3,010	$ 2,257
Total assets	3,921,643	3,535,656
Changes in net assets:
Contributions	274,201	261,594
Interest	526	644
Net depreciation in fair value of investments	(100,528)	(117,908)
Transfers between funds	469,668	368,489
Benefits paid to participants	(269,961)	(262,888)
Administrative expenses	(2,833)	(2,289)
Net increase	385,987	260,618
Short-term investment fund
Net assets:
Short-term investment fund and common stock	10,144	12,014
Short-term investment fund \| Oxy Stock Fund
Net assets:
Short-term investment fund and common stock	10,126	12,014
Common stock
Net assets:
Short-term investment fund and common stock	509,300	583,387
Common stock \| Oxy Stock Fund
Net assets:
Short-term investment fund and common stock	509,069	583,387
Interest and dividends	29	30
Total assets	519,224	595,431
Changes in net assets:
Contributions	115,592	110,796
Interest	12,073	10,585
Net depreciation in fair value of investments	(100,234)	(122,137)
Transfers between funds	(64,987)	(76,693)
Benefits paid to participants	(38,477)	(45,219)
Administrative expenses	(174)	(160)
Net increase	$ (76,207)	$ (122,828)

Plan Interest in Master Trust Accounts - Schedule of Fair Value Measurement (Details) - EBP 001 - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
EBP, Master Trust [Line Items]
Assets at fair value	$ 3,656,429	$ 3,244,537
DCP Master Trust
EBP, Master Trust [Line Items]
Assets at fair value	4,505,970	3,796,816
Total \| DCP Master Trust
EBP, Master Trust [Line Items]
Assets at fair value	654,485	587,093
Level 1 \| DCP Master Trust
EBP, Master Trust [Line Items]
Assets at fair value	654,485	587,093
Common stock \| Total \| DCP Master Trust
EBP, Master Trust [Line Items]
Assets at fair value	51,619	22,797
Common stock \| Level 1 \| DCP Master Trust
EBP, Master Trust [Line Items]
Assets at fair value	51,619	22,797
Mutual funds \| Total \| DCP Master Trust
EBP, Master Trust [Line Items]
Assets at fair value	602,866	564,296
Mutual funds \| Level 1 \| DCP Master Trust
EBP, Master Trust [Line Items]
Assets at fair value	602,866	564,296
Short-term investment fund \| NAV \| DCP Master Trust
EBP, Master Trust [Line Items]
Assets at fair value	793	872
Common/collective trusts \| NAV \| DCP Master Trust
EBP, Master Trust [Line Items]
Assets at fair value	$ 3,850,692	$ 3,208,851

Schedule H, Line 4i – Schedule of Assets (Held at End of Year) (Details) - EBP 001 $ in Thousands	12 Months Ended
	Dec. 31, 2025 USD ($) loan shares	Dec. 31, 2024
EBP, Schedule of Asset Held for Investment [Line Items]
Entity tax identification number	95-4035997
Plan number	001
Notes receivable from participants	$ 31,155
Plan interest in master trust accounts	3,366,650
Total	$ 3,917,249
Number of participant loans \| loan	2,319
Investment, Identifier [Axis]: Common stock \| Occidental Petroleum Corporation
EBP, Schedule of Asset Held for Investment [Line Items]
Investment, excluding plan interest in master trust	$ 509,300
Cost (in shares)	$ 372,626
Number of units (in shares) \| shares	12,385,694
Investment, Identifier [Axis]: Guaranteed Investment Contracts Master Trust
EBP, Schedule of Asset Held for Investment [Line Items]
Plan interest in master trust accounts	$ 229,665
Number of units (in shares) \| shares	10,379,779
Investment, Identifier [Axis]: Oxy Defined Contribution Plan Master Trust Account
EBP, Schedule of Asset Held for Investment [Line Items]
Plan interest in master trust accounts	$ 3,136,985
Investment, Identifier [Axis]: Short-Term Investment Fund \| BNY Short-Term Investment Fund
EBP, Schedule of Asset Held for Investment [Line Items]
Investment, excluding plan interest in master trust	$ 10,144
Number of units (in shares) \| shares	10,144,328
Minimum
EBP, Schedule of Asset Held for Investment [Line Items]
Interest rate	3.00%
Maximum
EBP, Schedule of Asset Held for Investment [Line Items]
Interest rate	11.00%	11.00%

Schedule H, Line 4j – Schedule of Reportable Transactions (Details) - EBP 001 $ in Thousands	12 Months Ended
	Dec. 31, 2025 USD ($)
EBP, Schedule of Reportable Transaction [Line Items]
Entity tax identification number	95-4035997
Plan number	001
Investment, Identifier [Axis]: Bank of New York \| 167 Acquisitions
EBP, Schedule of Reportable Transaction [Line Items]
Purchase Price	$ 106,205
Cost of Asset	106,205
Current Value of Asset on Transaction Date	106,205
Investment, Identifier [Axis]: Bank of New York \| 274 Dispositions
EBP, Schedule of Reportable Transaction [Line Items]
Selling Price	108,075
Cost of Asset	108,075
Current Value of Asset on Transaction Date	$ 108,075

Related-Party Transactions	12 Months Ended
Related-Party Transactions	Dec. 31, 2025
EBP 001
EBP, Related Party and Party-in-Interest Transactions [Line Items]
Related-Party Transactions	Related-Party Transactions The Trustee and Occidental are parties in interest as defined by ERISA. The Trustee invests certain Plan assets in its Collective Short-Term Investment Fund and the Oxy Stock Fund. Such transactions qualify as party-in-interest transactions permitted by the Department of Labor regulations. Occidental paid approximately $969,000 and $841,000 on behalf of the Plan to various vendors for the Plan’s administrative expenses during 2025 and 2024, respectively.

Risks and Uncertainties (Details) - EBP 001 - USD ($)	3 Months Ended
Risks and Uncertainties (Details) - EBP 001 - USD ($)	Mar. 31, 2026	Dec. 31, 2025	Dec. 31, 2024
EBP, Risk and Uncertainty [Line Items]
Average WTI price per barrel		$ 59.14
Subsequent Event
EBP, Risk and Uncertainty [Line Items]
Average WTI price per barrel	$ 71.93
Common stock
EBP, Risk and Uncertainty [Line Items]
Percent of investments in shares of common stock		13.00%	17.00%

Plan Interest in Master Trust Accounts - Change in Net Assets (Details) - EBP 001 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Net appreciation in fair value of investments:
Net appreciation	$ (100,528)	$ (117,908)
Net increase	385,987	260,618
DCP Master Trust
Net appreciation in fair value of investments:
Net appreciation	653,797	482,978
Interest and dividends	16,484	14,220
Less investment expenses	(427)	(606)
Investment income	669,854	496,592
Transfers in	581,926	555,260
Transfers out	(542,540)	(382,723)
Net increase	709,240	669,129
DCP Master Trust \| Common/collective trusts
Net appreciation in fair value of investments:
Net appreciation	613,220	449,174
DCP Master Trust \| Common stock
Net appreciation in fair value of investments:
Net appreciation	5,362	5,570
DCP Master Trust \| Mutual funds
Net appreciation in fair value of investments:
Net appreciation	35,215	28,234
GIC MTIA
Net appreciation in fair value of investments:
Interest Income	10,394	11,581
Less investment expenses	(438)	(386)
Investment income	9,956	11,195
Transfers in	54,082	39,934
Transfers out	(102,081)	(100,375)
Net increase	$ (38,043)	$ (49,246)

Guaranteed Investment Contracts Master Trust Account (Details) - Master Trust Balances - EBP 001 - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
EBP, Master Trust [Line Items]
Total investments	$ 331,318	$ 369,171
Short-term investment fund
EBP, Master Trust [Line Items]
Total investments	7,706	8,944
Common/collective trusts
EBP, Master Trust [Line Items]
Total investments	$ 323,612	$ 360,227

Cover	12 Months Ended
Cover	Dec. 31, 2025
Document Information [Line Items]
Document Type	11-K
Entity Registrant Name	Occidental Petroleum Corporation
Amendment Flag	false
Entity Central Index Key	0000797468
EBP 001
Document Information [Line Items]
Document Type	11-K
Entity Registrant Name	Occidental Petroleum Corporation
Amendment Flag	false
Entity Central Index Key	0000797468

Description of the Plan (Details) - EBP 001 - USD ($)	12 Months Ended
Description of the Plan (Details) - EBP 001 - USD ($)	Dec. 31, 2025	Dec. 31, 2024
EBP, Description of Plan [Line Items]
Non-highly compensated employees, employee contribution percentage limit	30.00%
Highly compensated employees, employee contribution percentage limit		15.00%
First employer matching percentage	200.00%
First percentage of eligible compensation	2.00%
Second employer matching percentage	100.00%
Second percentage of eligible compensation	3.00%
Percentage of eligible compensation	6.00%
Minimum borrowing amount	$ 1,000
Maximum borrowing amount	$ 50,000
Maximum borrowing amount, percentage of total vested account balance	50.00%
Monthly payroll deductions for repayment, percentage of monthly base compensation	25.00%
Loan term, minimum	1 year
Loan term, maximum	5 years
Primary residence loan term, minimum	6 years
Primary residence loan term, maximum	10 years
Minimum
EBP, Description of Plan [Line Items]
Before-tax contribution amount, percent of base pay	5.00%
Employer matching contributions	85.00%
Interest rate	3.00%
Maximum
EBP, Description of Plan [Line Items]
Employer matching contributions	100.00%
Interest rate	11.00%	11.00%

Tax Status	12 Months Ended
Tax Status	Dec. 31, 2025
EBP 001
EBP, Tax Status [Line Items]
Tax Status	Tax Status The Internal Revenue Service (IRS) has determined and informed Occidental, by a letter dated September 25, 2013, that the Plan and related trust are designed in accordance with applicable sections of the IRC. Although the Plan has been amended since receiving the determination letter, the Committees, using their judgment and the advice of their advisors, believe that the Plan is currently designed and operating in a manner that preserves its tax-qualified status, with the exceptions of certain immaterial operational errors that have been remedied in compliance with applicable programs of the IRS or the Department of Labor. U.S. GAAP requires plan management to evaluate tax positions taken by the Plan and recognize a tax liability (or asset) if the Plan has taken an uncertain position that more likely than not would not be sustained upon examination by the IRS. The Plan is subject to routine audits by the IRS; however, there are currently no audits for any tax periods in progress.

Statements of Net Assets Available for Benefits - EBP 001 - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
At fair value:
Plan interest in master trust accounts	$ 3,136,985	$ 2,649,136
Total investments at fair value	3,656,429	3,244,537
At contract value:
Plan interest in master trust accounts	229,665	258,996
Receivables:
Notes receivable from participants	31,155	29,520
Interest and dividends	3,010	2,257
Participant contribution	842	216
Employer contribution	542	130
Total receivables	35,549	32,123
Total assets	3,921,643	3,535,656
Net assets available for benefits	3,921,643	3,535,656
Short-term investment fund
At fair value:
Short-term investment fund and common stock	10,144	12,014
Common stock
At fair value:
Short-term investment fund and common stock	$ 509,300	$ 583,387

Description of the Plan	12 Months Ended
Description of the Plan	Dec. 31, 2025
EBP 001
EBP, Description of Plan [Line Items]
Description of the Plan	Description of the Plan The following description of the Occidental Petroleum Corporation Savings Plan (the Plan) provides only general information. Participants should refer to the Plan document for a more complete description of the Plan’s provisions. (a) General The Plan is a defined contribution plan generally available to certain employees of Occidental Petroleum Corporation (Occidental, or the employer), a Delaware corporation, and participating subsidiaries (collectively, the Company). The Plan is intended to be a tax-qualified plan containing a qualified cash or deferred arrangement and employee stock ownership plan. The Plan is subject to the provisions of the Employee Retirement Income Security Act of 1974, as amended (ERISA). (b) Plan Administration The Plan is administered by the Pension and Retirement Trust and Investment Committee as to investment decisions and by the Pension and Retirement Plan Administrative Committee as to all matters except investment decisions (these two committees are herein referred to collectively as the Committees). The Plan document provides that a fiduciary appointment officer has sole authority to appoint, remove, and monitor members of the Committees. The Committees have been given all powers necessary to carry out their respective duties, including, but not limited to, the power to administer and interpret the Plan and to answer all questions affecting eligibility of participants. Bank of New York Mellon Trust Company N. A. (the Trustee) is the trustee and custodian of the trust fund, which holds all of the assets of the Plan. (c) Contributions Participant Contributions – Each year, participants may contribute up to the maximum contribution percentage of compensation to the Plan on a before- or after-tax basis, or in any combination thereof, subject to certain Internal Revenue Code (IRC) limitations. For 2025 and 2024, the employee contribution percentage limits were 30% for non-Highly Compensated Employees (as defined in the Plan) and 15% for Highly Compensated Employees. Participants age 50 or older by the end of the Plan year were permitted to contribute additional before-tax catch-up contributions to the Plan up to $7,500 for each of 2025 and 2024. The Plan permits Roth contributions and in-plan Roth rollover contributions. Newly eligible participants who do not affirmatively elect to opt out of making contributions are automatically enrolled in the Plan with a before-tax contribution amount of 5% of base pay. Employer Matching Contributions – The employer matching contributions for non-collectively bargained employees is an amount equal to 200% of a participant’s contribution up to the first 2% of eligible compensation, and 100% of the next 3% of eligible compensation. Certain collectively bargained employees also fall under this matching formula, as negotiated by their respective unions. Other collectively bargained employees received employer matching contributions between 85% and 100%, as negotiated by their respective unions, up to the first 6% of eligible compensation that a participant contributes to the Plan. All employer contributions are invested in the Occidental Stock Fund (Oxy Stock Fund). All vested participants may elect to transfer their employer matching contributions to other investment funds. The Plan allows active employees who are eligible to participate in the Plan to roll over into the Plan all or part of the taxable money received in an eligible rollover distribution from another employer's tax-qualified retirement plan. (d) Participant Accounts All participant contributions and the earnings thereon are allocated to each participant’s accounts and are invested in accordance with the participant’s investment elections in accordance with Section 404(c) of ERISA. Participants who do not make an investment election are automatically enrolled in the Plan’s qualified default investment alternative. Each participant’s account is credited with the participant’s elected contribution, the employer’s respective matching contribution, and allocations of the respective fund’s investment income and losses and charged with investment manager fees. Allocations are based on participant earnings or account balances, as defined in the Plan. The benefit to which a participant is entitled is the benefit that can be provided from the participant’s vested account. (e) Vesting Participants are vested immediately in their contributions and employer matching contributions, plus actual earnings thereon. Participants are also fully vested in dividends paid on the portion of their employer matching contributions invested in the Oxy Stock Fund. (f) Notes Receivable From Participants Participants may borrow from their fund accounts a minimum of $1,000 up to a maximum amount equal to the lesser of (i) $50,000 reduced by the highest outstanding principal loan balance during the preceding 12 months, if any; (ii) 50% of their vested account balance; or (iii) an amount that would require monthly payroll deductions for repayment not greater than 25% of the participant's monthly base compensation. Loan terms may range from one to five years for general purpose loans and six to ten years for primary residence loans. The maturity dates on notes receivable from participants outstanding at December 31, 2025 range from January 2026 to November 2035. The loans are secured by the balance in the participant's account at the time the loan is approved. Loan interest rates are fixed on the first day of the month prior to the calendar month in which the loan is funded and rates are reasonable compared to similar loans issued by other lenders, in accordance with the Plan. Interest rates ranged from 3% to 11% on loans outstanding as of December 31, 2025 and 2024. Principal and interest are paid ratably through payroll deductions. (g) Distributions Generally, on termination of service, participants may elect to receive the vested portion of their account balance under one of the distribution options allowed by the Plan. Participants may elect to receive distributions from their vested account balance in the Oxy Stock Fund in cash or in shares of Occidental common stock. (h) Forfeited Accounts Forfeited nonvested accounts may be used to pay reasonable costs of administering the Plan and reduce employer contributions. As of December 31, 2025 and 2024, the balance of forfeited nonvested accounts was not material. Increases to the forfeiture account balance are primarily related to nonvested account balances of previously terminated participants and the forfeiture of unclaimed benefits, in accordance with the Plan document. These amounts are expected to be used to reduce future contributions, or reinstate account balances if such participants are located. During 2025 and 2024, no forfeitures were used to reduce employer contributions. (i) Expenses Certain administrative fees are paid by participants through their Plan accounts. Other expenses of maintaining the Plan are paid by the Company and are excluded from these financial statements. Investment related expenses are included in net appreciation (depreciation) in fair value of investments.

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2025
EBP 001
EBP, Subsequent Event [Line Items]
Subsequent Events	Subsequent Events In October 2025, the Company announced entry into a purchase and sale agreement with Berkshire Hathaway Inc. to sell all of the issued and outstanding equity interests in Occidental Chemical Corporation, a Texas corporation, and its consolidated subsidiaries (OxyChem). The sale was completed on January 2, 2026 (MEP Effective Date). Beginning on the MEP Effective Date, the Plan became a multiple-employer plan within the meaning of Code section 413(c). OxyChem was a participating subsidiary prior to the MEP Effective Date and continued to participate in the Plan after the MEP Effective Date. Effective on and after the MEP Effective Date, participants employed by OxyChem no longer receive employer matching contributions in the form of Occidental common stock. Employer matching contributions for OxyChem participants are invested in the Plan's qualified default investment alternative. OxyChem's participation in the Plan will cease no later than December 31, 2026. As soon as administratively practicable after this date the OxyChem participants' account balances in the Plan will be transferred out of the Plan to a 401(k) plan sponsored by OxyChem.

Risks and Uncertainties	12 Months Ended
Risks and Uncertainties	Dec. 31, 2025
EBP 001
EBP, Risk and Uncertainty [Line Items]
Risks and Uncertainties	Risks and Uncertainties The Plan invests in various types of investment securities. Investment securities are exposed to various risks, such as interest rate, market, and credit risks. Due to the level of risk associated with investment securities, it is at least reasonably possible that changes in the values of investment securities will occur in the near term and that such changes could materially affect participants’ account balances and the amounts reported in the statements of net assets available for benefits. Risks associated with the Oxy Stock Fund include those disclosed by Occidental in its annual report on Form 10-K filed with the U.S. Securities and Exchange Commission and its other public filings and disclosures. Additionally, some mutual funds invest in the securities of foreign companies, which involve special risks and considerations not typically associated with investing in U.S. companies. These risks include devaluation of currencies, less reliable information about issuers, different securities transaction clearance and settlement practices, and possible adverse political and economic developments. Moreover, securities of many foreign companies and their markets may be less liquid and their prices more volatile than similar types of securities of comparable U.S. companies. Certain derivative financial instruments are used by the Plan’s equity and fixed-income investment managers to remain fully invested in the asset class and to hedge currency risk. As of December 31, 2025 and 2024, approximately 13% and 17%, respectively, of total Plan investments were invested in shares of Occidental common stock. The Company's financial results are significantly influenced by oil prices and, to a lesser extent, NGL and natural gas prices, and commodity market differentials. The average WTI price per barrel for the three months ended March 31, 2026 was $71.93, compared to $59.14 for the three months ended December 31, 2025. Changes in oil prices could result in adjustments to capital investment levels and allocation, which may in turn impact production volumes. Oil prices are expected to remain volatile due to a number of factors, including heightened geopolitical risk, the evolving macro-economic environment and its effects on global energy demand, future actions by OPEC and non-OPEC oil producing nations, and ongoing shifts in U.S. trade policy. The ongoing conflict with Iran has significantly disrupted global crude oil and natural gas markets. The duration and trajectory of the conflict remains uncertain, contributing to ongoing commodity price volatility. Recent U.S. trade policy actions, including the introduction of tariff replacement measures, could also have implications for Occidental's business operations and financial performance. While the Company has not experienced a material impact to date, tariffs or tariff replacement measures imposed on the Company's suppliers could increase costs over time, and broader macroeconomic effects of policy changes and uncertainty could affect demand for the Company's products and its realized prices.

Reconciliation of the Financial Statements to the Form 5500 - Reconciliation of Benefits Paid (Details) - EBP 001 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
EBP, Reconciliation of Financial Statement to Form 5500 [Line Items]
Benefits paid to participants per the financial statements	$ 269,961	$ 262,888
Amounts allocated to withdrawing participants at December 31, 2025 and 2024	(465)	(178)
Amounts allocated to withdrawing participants at December 31, 2024 and 2023	2,286	465
Benefits paid to participants per the Form 5500	$ 271,782	$ 263,175

Plan Termination	12 Months Ended
Plan Termination	Dec. 31, 2025
EBP 001
EBP, Description of Plan [Line Items]
Plan Termination	Plan Termination Although it has not expressed any intent to do so, Occidental has the right under the Plan’s provisions to discontinue its contributions at any time and to terminate the Plan subject to the provisions of ERISA.

Fair Value Measurements	12 Months Ended
Fair Value Measurements	Dec. 31, 2025
EBP 001
EBP, Investment, Fair Value and NAV [Line Items]
Fair Value Measurements	Fair Value Measurements Plan assets are measured at fair value, based on the priorities of the inputs to valuation techniques used to measure fair value, in a three-level fair value hierarchy: Level 1 – using quoted prices in the active markets for identical assets or liabilities; Level 2 – using observable inputs other than quoted prices for identical assets or liabilities; and Level 3 – using unobservable inputs. Transfers between levels, if any, are recognized at year end. The following is a description of the valuation methodologies used for the Plan assets that are measured at fair value. See Note 5 and Note 6 for tables that set forth by level, within the fair value hierarchy, the Plan’s assets at fair value as of December 31, 2025 and 2024. (a) Common Stocks and Preferred Stocks Common stocks and preferred stocks are valued at the closing price reported on the active market on which the individual securities are traded. (b) Mutual Funds Generally, mutual funds are valued at the net asset value (NAV) of the shares held by the Plan. If publicly registered, the value of the mutual fund can be obtained through quoted market prices in active markets. (c) Short-Term Investment Fund The short-term investment fund is valued at the NAV of the shares held by the Plan. (d) Common/Collective Trusts The common/collective trusts are valued at the NAV of the units provided by the fund issuer. The NAV, as provided by the trustee, is used as a practical expedient to estimate fair value. The NAV is based on the fair value of the underlying investments held by the fund less liabilities. As of December 31, 2025 and 2024, there were no redemption restrictions on these investments. (e) Corporate Bonds Corporate bonds are valued using quoted market price when available. If quoted market prices are not observable, corporate bonds are valued using pricing models with market observable inputs from both active and non-active markets.

Statement of Changes in Net Assets Available for Benefits - EBP 001 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Investment income (loss):
Interest	$ 526	$ 644
Dividends	11,907	10,449
Net depreciation in fair value of investments	(100,528)	(117,908)
Plan interest in master trust accounts investment income	469,668	368,489
Total investment income	381,573	261,674
Interest income on notes receivable from participants	3,007	2,527
Contributions:
Participant	149,471	140,691
Employer	110,775	102,366
Participant rollovers	13,955	18,537
Total contributions	274,201	261,594
Deductions:
Benefits paid to participants	269,961	262,888
Administrative expenses	2,833	2,289
Total deductions	272,794	265,177
Net increase	385,987	260,618
Net assets available for benefits:
Beginning of year	3,535,656	3,275,038
End of year	$ 3,921,643	$ 3,535,656

Plan Interest in Master Trust Accounts - Schedule of Net Assets Held (Details) - EBP 001 - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
At fair value:
Plan interest in master trust accounts, at fair value	$ 3,656,429	$ 3,244,537
Receivables:
Accrued investment income	3,010	2,257
Total receivables	35,549	32,123
Total assets	3,921,643	3,535,656
Liabilities:
Net assets available for benefits	3,921,643	3,535,656	$ 3,275,038
DCP Master Trust
At fair value:
Plan interest in master trust accounts, at fair value	$ 4,505,970	$ 3,796,816
Liabilities:
Plan's percentage interest in Master Trust net assets	70.00%	70.00%
GIC MTIA
Liabilities:
Plan's percentage interest in Master Trust net assets	69.00%	70.00%
Master Trust Balances
At contract value:
Total investments	$ 331,318	$ 369,171
Master Trust Balances \| DCP Master Trust
At fair value:
Plan interest in master trust accounts, at fair value	4,505,970	3,796,816
At contract value:
Cash and cash equivalents	0	14
Receivables:
Accrued investment income	810	464
Total assets	4,506,780	3,797,294
Liabilities:
Due to broker for securities purchased	436	190
Total liabilities	436	190
Net assets available for benefits	4,506,344	3,797,104
Master Trust Balances \| GIC MTIA
At contract value:
Total investments	331,318	369,171
Receivables:
Accrued investment income	838	922
Total receivables	838	922
Total assets	332,156	370,093
Liabilities:
Accrued expenses	106	0
Total liabilities	106	0
Net assets available for benefits	332,050	370,093
Master Trust Balances \| Short-term investment fund
At contract value:
Total investments	7,706	8,944
Master Trust Balances \| Short-term investment fund \| DCP Master Trust
At fair value:
Plan interest in master trust accounts, at fair value	793	872
Master Trust Balances \| Short-term investment fund \| GIC MTIA
At contract value:
Total investments	7,706	8,944
Master Trust Balances \| Common/collective trusts
At contract value:
Total investments	323,612	360,227
Master Trust Balances \| Common/collective trusts \| DCP Master Trust
At fair value:
Plan interest in master trust accounts, at fair value	3,850,692	3,208,851
Master Trust Balances \| Common/collective trusts \| GIC MTIA
At contract value:
Total investments	323,612	360,227
Master Trust Balances \| Common stock \| DCP Master Trust
At fair value:
Plan interest in master trust accounts, at fair value	51,619	22,797
Master Trust Balances \| Mutual funds \| DCP Master Trust
At fair value:
Plan interest in master trust accounts, at fair value	602,866	564,296
Plan's Interest in Master Trust Balances
At fair value:
Plan interest in master trust accounts, at fair value	3,136,985	2,649,136
At contract value:
Total investments	229,665	258,996
Liabilities:
Net assets available for benefits	3,366,650	2,908,132
Plan's Interest in Master Trust Balances \| DCP Master Trust
At fair value:
Plan interest in master trust accounts, at fair value	3,136,725	2,648,935
At contract value:
Cash and cash equivalents	0	10
Receivables:
Accrued investment income	564	324
Total assets	3,137,289	2,649,269
Liabilities:
Due to broker for securities purchased	304	133
Total liabilities	304	133
Net assets available for benefits	3,136,985	2,649,136
Plan's Interest in Master Trust Balances \| GIC MTIA
At contract value:
Total investments	229,159	258,351
Receivables:
Accrued investment income	579	645
Total receivables	579	645
Total assets	229,738	258,996
Liabilities:
Accrued expenses	73	0
Total liabilities	73	0
Net assets available for benefits	229,665	258,996
Plan's Interest in Master Trust Balances \| Short-term investment fund \| DCP Master Trust
At fair value:
Plan interest in master trust accounts, at fair value	552	608
Plan's Interest in Master Trust Balances \| Short-term investment fund \| GIC MTIA
At contract value:
Total investments	5,330	6,259
Plan's Interest in Master Trust Balances \| Common/collective trusts \| DCP Master Trust
At fair value:
Plan interest in master trust accounts, at fair value	2,680,569	2,238,728
Plan's Interest in Master Trust Balances \| Common/collective trusts \| GIC MTIA
At contract value:
Total investments	223,829	252,092
Plan's Interest in Master Trust Balances \| Common stock \| DCP Master Trust
At fair value:
Plan interest in master trust accounts, at fair value	35,933	15,905
Plan's Interest in Master Trust Balances \| Mutual funds \| DCP Master Trust
At fair value:
Plan interest in master trust accounts, at fair value	$ 419,671	$ 393,694

Summary of Significant Accounting Policies (Policies) - EBP 001	12 Months Ended
	Dec. 31, 2025
EBP, Accounting Policy [Line Items]
Basis of Accounting	Basis of Accounting The financial statements of the Plan are prepared on the accrual method of accounting.
Use of Estimates	Use of Estimates The process of preparing financial statements in conformity with United States generally accepted accounting principles (U.S. GAAP) requires management to make informed estimates and judgments regarding certain types of financial statement balances and disclosures. Changes in facts and circumstances or discovery of new information relating to such transactions and events may result in revised estimates and judgments and actual results may differ from estimates upon settlement but generally not by material amounts. Management believes that these estimates and judgments provide a reasonable basis for the fair presentation of the Plan’s financial statements.
Investment Valuation and Income Recognition	Investment Valuation and Income Recognition The Plan’s investments are reported at fair value, with the exception of fully benefit-responsive investment contracts, which are reported at contract value. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. See Note 3 for a discussion of fair value measurements. See Note 4 for a discussion of contract value investments. Purchases and sales of securities are recorded on a trade-date basis. Interest income is recorded on an accrual basis. Dividends are recorded on the ex-dividend date. Net appreciation (depreciation) in fair value of investments includes gains and losses on investments bought and sold as well as held during the year.
Contributions	Contributions Contributions from Plan participants and employer matching contributions are recorded in the year in which the employee contributions are withheld from compensation.
Payment of Benefits	Payment of Benefits Benefits are recorded when paid.
Notes Receivable From Participants	Notes Receivable From Participants Notes receivable from participants are measured at their unpaid principal balance, plus any accrued but unpaid interest and classified as a note receivable in the accompanying statements of net assets available for benefits. Delinquent notes receivable from participants are reclassified as distributions based upon the terms of the Plan.
Reclassifications	Reclassifications Certain amounts in prior years have been reclassified to conform to the current year’s presentation.

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2025
EBP 001
EBP, Accounting Policy [Line Items]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies (a) Basis of Accounting The financial statements of the Plan are prepared on the accrual method of accounting. (b) Use of Estimates The process of preparing financial statements in conformity with United States generally accepted accounting principles (U.S. GAAP) requires management to make informed estimates and judgments regarding certain types of financial statement balances and disclosures. Changes in facts and circumstances or discovery of new information relating to such transactions and events may result in revised estimates and judgments and actual results may differ from estimates upon settlement but generally not by material amounts. Management believes that these estimates and judgments provide a reasonable basis for the fair presentation of the Plan’s financial statements. (c) Investment Valuation and Income Recognition The Plan’s investments are reported at fair value, with the exception of fully benefit-responsive investment contracts, which are reported at contract value. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. See Note 3 for a discussion of fair value measurements. See Note 4 for a discussion of contract value investments. Purchases and sales of securities are recorded on a trade-date basis. Interest income is recorded on an accrual basis. Dividends are recorded on the ex-dividend date. Net appreciation (depreciation) in fair value of investments includes gains and losses on investments bought and sold as well as held during the year. (d) Contributions Contributions from Plan participants and employer matching contributions are recorded in the year in which the employee contributions are withheld from compensation. (e) Payment of Benefits Benefits are recorded when paid. (f) Notes Receivable From Participants Notes receivable from participants are measured at their unpaid principal balance, plus any accrued but unpaid interest and classified as a note receivable in the accompanying statements of net assets available for benefits. Delinquent notes receivable from participants are reclassified as distributions based upon the terms of the Plan. (g) Reclassifications Certain amounts in prior years have been reclassified to conform to the current year’s presentation.

Reconciliation of the Financial Statements to the Form 5500 - Reconciliation of Net Assets Available for Benefit (Details) - EBP 001 - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
EBP, Reconciliation of Financial Statement to Form 5500 [Line Items]
Net assets available for benefits per the financial statements	$ 3,921,643	$ 3,535,656	$ 3,275,038
Amounts allocated to withdrawing participants	(2,286)	(465)
Net assets available for benefits per the Form 5500	$ 3,919,357	$ 3,535,191