Updated MRE For The Nelligan Joint Venture Project

TORONTO - IAMGOLD Corporation announced an updated Mineral Resource Estimate (MRE) for the Nelligan Joint Venture Project, located 60 kilometers southwest of Chibougamau, Quebec, Canada. The Nelligan Joint Venture Project updated MRE comprises (on a 100% basis using a US$1,500 per ounce gold price): 72.2 million tonnes of Indicated Mineral Resources averaging 0.85 grams of gold per tonne for 1.97 million ounces of gold; 114.1 million tonnes of Inferred Mineral Resources averaging 0.88 grams of gold per tonne for 3.24 million ounces of gold; Mineral Resources have increased by 92% in tonnage, with a 15% decline in gold grades, for an overall gain of 63% in metal content - relative to the 2019 Mineral Resource estimate; Additional infill drilling completed from 2020 to 2022 and refinement of the deposit and structural models contributed to the conversion of 62% of Inferred Mineral Resources to an Indicated Mineral Resource category relative to the 2019 Mineral Resource estimate; and Potential highlighted for further resource expansion.

The estimate was completed in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Definition Standards incorporated by reference in National Instrument 43-101 - Standards of Disclosure for Mineral Projects (NI 43-101).

Craig MacDougall, Executive Vice President, Growth, said, "We are very pleased to see that our drilling programs have confirmed the anticipated expansion potential at Nelligan resulting in a significant increase of Mineral Resources within a wide and persistent mineralized system. This Mineral Resource estimation has not only resulted in a significant increase in resources, but also resulted in upgrading nearly 2 million ounces from Inferred to an Indicated resource classification. Potential for further resource expansion appears favorable, noting that the deposit has areas within the resource pit shell, along strike and at depth that remain open for further drilling. Our exploration efforts continue to highlight the significance of this pure grass-root discovery."