IAMGOLD CORP

Nelligan Mining Complex, Quebec, Canada

On December 19, 2025, and December 22, 2025, the Company acquired all of the issued and outstanding shares of each of Northern Superior and Orbec, respectively, by way of court-approved plan of arrangement for consideration of approximately $329.0 million and $14.2 million, respectively, in shares of the Company and cash. The Northern Superior acquisition consolidated the Philibert, Chevrier, Lac Surprise, and Croteau projects with Orbec’s early‑stage Muus project, creating a combined project portfolio alongside IAMGOLD’s Nelligan, Monster Lake and Anik projects.

The combined assets, together the “Nelligan Mining Complex”, consolidates the Chibougamau region with a dominant land position of approximately 134,000 hectares. The Nelligan Mining Complex is now positioned as one of the largest pre-production gold camps in Canada. The close proximity of the primary deposits to each other supports the conceptual vision of a central processing facility being fed from multiple ore sources within a 17-kilometre radius.

On February 17, 2026, the Company announced its updated Mineral Resources for the Nelligan Mining Complex. On a consolidated basis, the Nelligan Mining Complex reported a significant increase in Indicated and Inferred Mineral Resources. Indicated Resources increased 1.1 million ounces to a total of 4.3 million ounces at an average grade of 0.99 g/t Au. Inferred ounces increased 1.9 million ounces to a total of 7.5 million ounces at an average grade of 1.08 g/t Au. At the time of the Northern Superior acquisition, disclosed estimates were 3.75 Moz Au Measured and Indicated Mineral Resources and 8.65 Moz Au Inferred Mineral Resources, which included Croteau. The Company opted to exclude the mineral resources previously associated with the Croteau property in its year-end update, resulting in the reported totals above.

The Company plans to issue an inaugural technical report for the Nelligan Mining Complex during the first half of 2027.

IAMGOLD has budgeted approximately $24 million for exploration activities within the Nelligan Mining Complex for 2026. The goal of the program will be to conduct thorough testing of Philibert, expand Nelligan and continue to test Monster Lake at depth, all in support of a conceptual preliminary economic assessment in 2027. The Company is planning to test high priority targets within the region.

In January 2026, the Company exercised the option to acquire the remaining 25% interest in the Philibert property held by SOQUEM for the payment totaling C$3.5 million, completing the consolidation of 100% of the Philibert property.