Anita Soni

Tanya Jakusconek

Carey MacRury

Mohamed Sidibe

Steven Green

Lawson Winder

Matthew Murphy

Michael Parkin

Wayne Lam

- IAMGOLD Corporation announced positive assay results from its **2025 drilling programs** at the Nelligan and Monster Lake Projects in central Quebec, Canada, confirming the extension of mineralized zones.  **[1203464_0001062993-25-015714_exhibit99-1.htm:0]** 
- The combined Nelligan and Monster Lake camp now boasts nearly **9 million ounces of resources**, positioning Nelligan among Canada's largest gold projects.  **[1203464_0001062993-25-015714_exhibit99-1.htm:0]** 
- Significant drilling intercepts at Nelligan include **20.6 meters at 1.93 g/t Au** in Zone 36 and **13.5 meters at 3.15 g/t Au** in the Renard Zone.  **[1203464_0001062993-25-015714_exhibit99-1.htm:0]** 
- High-grade results from Monster Lake include **9.0 meters at 23.4 g/t Au** in the Megane Zone and **4.9 meters at 127.3 g/t Au** in the Lower Shear Zone.  **[1203464_0001062993-25-015714_exhibit99-1.htm:0]** 
- As of December 31, 2024, Nelligan's estimated Mineral Resources comprise **3.1 million ounces of Indicated Resources** and **5.2 million ounces of Inferred Resources**, while Monster Lake's estimated Mineral Resources include **84,200 ounces of Indicated Resources** and **488,500 ounces of Inferred Resources**.  **[1203464_0001062993-25-015714_exhibit99-1.htm:2]** **[1203464_0001062993-25-015714_exhibit99-1.htm:3]**

IAMGOLD Announces Positive Drilling Results and Resource Extensions at Nelligan and Monster Lake Projects

IAMGOLD (IAG)