Transocean Ltd.

​ Commission file number 001-38373 ​ Transocean Ltd. (Exact name of registrant as specified in its charter) ​ ​ Switzerland 98-0599916 (State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification No.) ​ ​ Turmstrasse 30 Steinhausen , Switzerland 6312 (Address of principal executive offices) (Zip Code) ​ ​ ​ +41 (41) 749-0500 (Registrant's telephone number, including area code) ​ ​ ​

TRANSOCEAN LTD. AND SUBSIDIARIES INDEX TO QUARTERLY REPORT ON FORM 10-Q QUARTER ENDED MARCH 31, 2026 ​

Condensed Consolidated Statements of Operations

Condensed Consolidated Statements of Comprehensive Income (Loss )

Condensed Consolidated Statements of Equity

Condensed Consolidated Statements of Cash Flows

Notes to Condensed Consolidated Financial Statements

Management's Discussion and Analysis of Financial Condition and Results of Operations

Quantitative and Qualitative Disclosures About Market Risk

Unregistered Sales of Equity Securities and Use of Proceeds

PART I. FINANCIAL INFORMATION Item I. Financial Statements

​ ​ TRANSOCEAN LTD. AND SUBSIDIARIES CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (in millions, except per share data) (Unaudited) ​ ​

TRANSOCEAN LTD. AND SUBSIDIARIES CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (in millions) (Unaudited) ​ ​

​ ​ Three months ended ​ ​ ​ March 31, ​ ​ ​ ​ 2026 ​ ​ 2025 ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) ​ $ 71 ​ $ ( 79 ) ​ ​ ​ ​ ​ ​ ​ ​ ​ Components of net periodic benefit costs before reclassifications ​ ​ 5 ​ ​ ( 3 ) ​ Components of net periodic benefit costs reclassified to net loss ​ ​ - ​ ​ - ​ Other comprehensive income (loss) before income taxes ​ ​ 5 ​ ​ ( 3 ) ​ Income taxes related to other comprehensive income (loss) ​ ​ - ​ ​ - ​ ​ ​ ​ ​ ​ ​ ​ ​ Other comprehensive income (loss) ​ ​ 5 ​ ​ ( 3 ) ​ ​ ​ ​ ​ ​ ​ ​ ​ Total comprehensive income (loss) ​ $ 76 ​ $ ( 82 ) ​

TRANSOCEAN LTD. AND SUBSIDIARIES CONDENSED CONSOLIDATED BALANCE SHEETS (in millions, except par value) (Unaudited) ​ ​

TRANSOCEAN LTD. AND SUBSIDIARIES CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (in millions) (Unaudited) ​ ​

TRANSOCEAN LTD. AND SUBSIDIARIES CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (in millions) (Unaudited) ​ ​

​ ​ Three months ended ​ ​ ​ March 31, ​ ​ ​ ​ ​ 2026 ​ ​ ​ 2025 ​ ​ Cash flows from operating activities ​ ​ ​ ​ ​ ​ ​ Net income (loss) $ 71 ​ $ ( 79 ) ​ Adjustments to reconcile to net cash provided by operating activities: ​ ​ ​ ​ ​ ​ ​ Depreciation and amortization ​ ​ 143 ​ ​ 176 ​ Share-based compensation expense ​ ​ 8 ​ ​ 8 ​ Gain on disposal of assets, net ​ ​ ( 4 ) ​ ​ ( 2 ) ​ Amortization of debt-related balances, net ​ ​ 10 ​ ​ 13 ​ (Gain) loss on adjustment to bifurcated compound exchange feature ​ ​ 153 ​ ​ ( 36 ) ​ Loss on retirement of debt ​ ​ 11 ​ ​ - ​ Deferred income tax expense (benefit) ​ ​ ( 73 ) ​ ​ 15 ​ Other, net ​ ​ ( 1 ) ​ ​ 4 ​ Changes in contract liabilities, net ​ ​ ( 42 ) ​ ​ ( 38 ) ​ Changes in deferred costs, net ​ ​ 31 ​ ​ ( 12 ) ​ Changes in other operating assets and liabilities, net ​ ​ ( 143 ) ​ ​ ( 23 ) ​ Net cash provided by operating activities ​ ​ 164 ​ ​ 26 ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash flows from investing activities ​ ​ ​ ​ ​ ​ ​ Capital expenditures ​ ​ ( 28 ) ​ ​ ( 60 ) ​ Proceeds from disposal of assets, net of costs to sell ​ ​ 25 ​ ​ 2 ​ Proceeds from disposal of investment in note receivable from unconsolidated affiliate ​ ​ 13 ​ ​ - ​ Net cash provided by (used in) investing activities ​ ​ 10 ​ ​ ( 58 ) ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash flows from financing activities ​ ​ ​ ​ ​ ​ ​ Repayments of debt ​ ​ ( 556 ) ​ ​ ( 210 ) ​ Other, net ​ ​ - ​ ​ ( 8 ) ​ Net cash used in financing activities ​ ​ ( 556 ) ​ ​ ( 218 ) ​ ​ ​ ​ ​ ​ ​ ​ ​ Net decrease in unrestricted and restricted cash and cash equivalents ​ ​ ( 382 ) ​ ​ ( 250 ) ​ Unrestricted and restricted cash and cash equivalents, beginning of period ​ ​ 997 ​ ​ 941 ​ Unrestricted and restricted cash and cash equivalents, end of period $ 615 ​ $ 691 ​

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quarterly period ending March 31, 2028. We continue to evaluate the requirements. Although our adoption will require us to augment certain disclosures in the notes to consolidated financial statements, we do not expect such adoption to have a material effect on our consolidated statements of financial position, operations or cash flows. Note 4 - Revenues Overview - For most of our contracts with customers, our drilling services represent a single performance obligation that is satisfied over time, the duration of which varies by contract. As of March 31, 2026, the drilling contract with the longest expected remaining duration, excluding unexercised options, extends through November 2030. Disaggregation - Our contract drilling revenues, disaggregated by asset group and by country in which they were earned, were as follows (in millions): ​ ​

​ ​ Three months ended March 31, ​ ​ ​ 2026 ​ 2025 ​ ​ ​ Ultra- ​ Harsh ​ ​ ​ Ultra- ​ Harsh ​ ​ ​ ​ ​ deepwater ​ environment ​ ​ ​ deepwater ​ environment ​ ​ ​ ​ ​ floaters ​ floaters ​ Total ​ floaters ​ floaters ​ Total ​ U.S. $ 433 ​ $ - ​ $ 433 ​ $ 394 ​ $ - ​ $ 394

(a) The aggregate contract drilling revenues earned in other countries that individually represented less than 10 percent of total contract drilling revenues.

Contract liabilities - Contract liabilities for our contracts with customers were as follows (in millions): ​ ​

Deferred contract revenues, recorded in other current liabilities $ 156 ​ $ 181 ​ Deferred contract revenues, recorded in other long-term liabilities ​ ​ 75 ​ ​ 92 ​ Total contract liabilities $ 231 ​ $ 273 ​

Significant changes in contract liabilities were as follows (in millions): ​

​ ​ Three months ended March 31, ​ ​ ​ 2026 ​ 2025 ​ Total contract liabilities, beginning of period ​ $ 273 ​ $ 443 ​ Decrease due to recognition of revenues for goods and services ​ ​ ( 65 ) ​ ​ ( 62 ) ​ Increase due to goods and services transferred over time ​ ​ 23 ​ ​ 24 ​ Total contract liabilities, end of period ​ $ 231 ​ $ 405 ​

​ Pre-operating costs - In the three months ended March 31, 2026 and 2025, we recognized pre-operating costs of $ 38 million and $ 37 million, respectively, recorded in operating and maintenance costs. At March 31, 2026 and December 31, 2025, the carrying amount of our unrecognized pre-operating costs to obtain contracts was $ 101 million and $ 136 million, respectively, recorded in other assets. Note 5 - Long-Lived Assets Assets held for sale - At March 31, 2026, the aggregate carrying amount of our assets held for sale, including the harsh environment semisubmersible Henry Goodrich, together with related assets, was $ 1 million. At December 31, 2025, the aggregate carrying amount of our assets held for sale, including the ultra-deepwater drillships Deepwater Champion , Discoverer India and the harsh environment semisubmersible Henry Goodrich , together with related assets, was $ 24 million. Disposals - In the three months ended March 31, 2026, we completed the sale of Deepwater Champion and Discoverer India , together with related assets, for aggregate net cash proceeds of $ 27 million, including $ 3 million received as a deposit in the year ended December 31, 2025. In the three months ended March 31, 2026, we recognized an aggregate net gain of $ 4 million associated with the disposal of the rigs and related assets. - 7 -

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Note 6 - Debt Overview Outstanding debt - The aggregate principal amounts and aggregate carrying amounts, including a bifurcated compound exchange feature and unamortized debt-related balances, such as discounts, premiums and issue costs, were as follows (in millions): ​ ​

​ ​ Principal amount ​ ​ Carrying amount

​ ​ March 31, ​ December 31, ​ March 31, ​ December 31,

​ Scheduled installments and maturities - At March 31, 2026, scheduled repayments were as follows (in millions): ​ ​

Twelve months ending March 31, ​ ​ ​ ​ 2027 ​ $ 338 ​ 2028 ​ ​ 220 ​ 2029 ​ ​ 457 ​ 2030 ​ ​ 1,629 ​ 2031 ​ ​ - ​ Thereafter ​ ​ 2,493 ​ Total principal amount of debt ​ ​ 5,137 ​ Total unamortized debt-related balances, net ​ ​ ( 142 ) ​ Bifurcated compound exchange feature, at estimated fair value ​ ​ 279 ​ Total carrying amount of debt ​ $ 5,274 ​

​ Credit agreement Secured Credit Facility - We have a secured revolving credit facility established under a bank credit agreement (as amended from time to time, the "Secured Credit Facility"), which has a borrowing capacity of $ 510 million through its maturity on June 22, 2028. Throughout the term of the Secured Credit Facility, we pay a facility fee on the amount of the underlying commitment, which ranges from 0.375 percent to 1.00 percent based on the credit rating of the Secured Credit Facility. We may borrow under the Secured Credit Facility at a forward-looking term rate based on the secured overnight financing rate ("Term SOFR") plus a margin and a Term SOFR spread adjustment of 0.10 percent. The Secured Credit Facility is subject to permitted extensions and certain early maturity triggers, including if on any date the aggregate amount of scheduled principal repayments of indebtedness, with certain exceptions, due within 91 days thereof is equal to or in excess of $ 325 million and available cash is less than $ 250 million. The Secured Credit Facility permits us to increase the aggregate amount of commitments by up to $ 250 million. The Secured Credit Facility is guaranteed by Transocean Ltd. and certain wholly owned subsidiaries. At March 31, 2026, based on the credit rating of the Secured Credit Facility as of that date, the Secured Credit Facility Margin was 2.875 percent and the facility fee was 0.625 percent. At March 31, 2026, we had no borrowings outstanding, $ 48 million of letters of credit issued, and we had $ 462 million of available borrowing capacity under the Secured Credit Facility. - 8 -

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Exchangeable bonds Interest expense - We recognized interest expense for our exchangeable bonds as follows (in millions): ​ ​

​ ​ Three months ended ​ ​ ​ March 31, ​ ​ ​ 2026 ​ 2025 ​ Contractual interest ​ $ 3 ​ $ 5 ​ Amortization ​ ​ 5 ​ ​ 6 ​ (Gain) loss on adjustment to bifurcated compound exchange feature ​ ​ 153 ​ ​ ( 36 ) ​ Total ​ $ 161 ​ $ ( 25 ) ​

​ Effective March 30, 2026, we may redeem for cash all or a portion of the 4.625 % senior guaranteed exchangeable bonds due September 2029 (the " 4.625 % Exchangeable Bonds") at a price equivalent to the aggregate principal amount to be redeemed if the closing price of our shares has been greater than 115 percent of the exchange price for a period of at least 20 trading days. If we give notice of our election to exercise the right to redeem, the indenture governing the 4.625 % Exchangeable Bonds contains a compound exchange feature that, in addition to the exchange terms presented below, requires us to pay a make-whole premium of future interest through March 30, 2028 to any holders that exercise their right to exchange during the redemption notice period. Such compound exchange feature must be bifurcated from the host debt instrument since it is not considered indexed to our stock. Accordingly, we recognize changes to the liability for the estimated fair value of the bifurcated compound exchange feature with a corresponding adjustment to interest expense. At March 31, 2026 and December 31, 2025, the carrying amount of the bifurcated compound exchange feature, recorded as a component of the carrying amount of debt, was $ 279 million and $ 126 million, respectively. Effective interest rate and fair value - At March 31, 2026, the 4.625 % Exchangeable Bonds had an effective interest rate of 18.3 % and an estimated fair value of $ 522 million. We estimated the fair value of the exchangeable debt instrument, including the exchange feature, by employing a binomial lattice model using significant other observable inputs, representative of Level 2 fair value measurements, including the terms and credit spreads of our debt and the expected volatility of the market price for our shares. Exchange terms - At March 31, 2026, the 4.625 % Exchangeable Bonds had the following exchange terms: (a) an exchange rate of 290.6618 Transocean Ltd. shares per $1,000 note, (b) an implied exchange price of $ 3.44 per Transocean Ltd. share and (c) an aggregate of 75.3 million shares issuable upon exchange of our exchangeable bonds. The exchange rate is subject to adjustment upon the occurrence of certain events. The 4.625 % Exchangeable Bonds may be exchanged by holders at any time prior to the close of business on the second business day immediately preceding the maturity date or redemption date and, at our election, such exchange may be settled by delivering cash, Transocean Ltd. shares or a combination of cash and shares. Redemption and retirement In March 2026, after making the scheduled installment of $ 67 million to repay an equivalent aggregate principal amount of the 8.375 % senior secured notes due February 2028, we made a cash payment of $ 365 million, including an early redemption premium, to retire the outstanding $ 358 million aggregate principal amount of the notes. In the three months ended March 31, 2026, as a result of the early redemption, we recognized a loss of $ 11 million associated with the retirement of debt. Note 7 - Income Taxes Tax provision and rate - In the three months ended March 31, 2026 and 2025, our effective tax rate was ( 335.3 ) percent and ( 95.8 ) percent, respectively, based on income or loss before income taxes. In the three months ended March 31, 2026 and 2025, the effect of various discrete period tax items was a net tax benefit of $ 113 million and a net tax expense of $ 14 million, respectively. In the three months ended March 31, 2026, such discrete items included changes to operating structures, various uncertain tax positions and valuation allowances. In the three months ended March 31, 2025, such discrete items included changes to various uncertain tax positions and valuation allowances. In the three months ended March 31, 2026 and 2025, our effective tax rate, excluding discrete items, was 192.0 percent and ( 62.3 ) percent, respectively, based on income or loss before income taxes. Tax positions and returns - We conduct operations through our various subsidiaries in countries throughout the world. Each country has its own tax regimes with varying nominal rates, deductions and tax attributes that are subject to changes resulting from new legislation, interpretation or guidance. From time to time, as a result of these changes, we may revise previously evaluated tax positions, which could cause us to adjust our recorded tax assets and liabilities. Tax authorities in certain jurisdictions are examining our tax returns and, in some cases, have issued assessments. We intend to defend our tax positions vigorously. Although we can provide no assurance as to the outcome of the aforementioned changes, examinations or assessments, we do not expect the ultimate liability to have a material adverse effect on our condensed consolidated statement of financial position or results of operations; however, it could have a material adverse effect on our condensed consolidated statement of cash flows. Brazil tax investigations - In December 2005, the Brazilian tax authorities began issuing tax assessments with respect to our tax returns for the years 2000 through 2004. In May 2014, the Brazilian tax authorities issued an additional tax assessment for the years 2009 and 2010. We filed protests with the Brazilian tax authorities for the assessments and are engaged in the appeals process, and a portion of - 9 -

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