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Lamgold Reports Increase IN Mineral Reserves and Resources at Existing Assets, with Increase IN Resources at Gosselin

Resource Estimates

NEWS RELEASE TSX: IMG NYSE: IAG

lAMGOLD REPORTS INCREASE IN MINERAL RESERVES AND RESOURCES AT

EXISTING ASSETS, WITH INCREASE IN RESOURCES AT GOSSELIN

All amounts are in US dollars, unless otherwise indicated.

Measured and indicated resources are quoted inclusive of proven and probable reserves for all sites and projects.

Toronto, Ontario, February 15, 2024 – IAMGOLD Corporation (NYSE:IAG) (TSX:IMG) (“IAMGOLD” or the

“Company”) announces its updated Mineral Reserves and Mineral Resources statement as of December 31, 2023

prepared in accordance with National Instrument 43 -101 – Standards of Disclosure for Mineral Projects (“NI 43-

101”). A summary table of the updated Mineral Resources and Reserves for the Company’s current assets ,

including attributable ounces accounting for ownership interest, can be found at the end of this news release.

Highlights

• Updated Gosselin Mineral Resource estimate (100% basis) of 4.4 million Indicated gold ounces in 161.3

million tonnes (“Mt”) at 0.85 grams per tonne gold (“g/t Au”), and 3.0 million Inferred ounces (123.9 Mt at

0.75 g/t Au). This represents an estimated increase of 1.1 million ounces in Indicated and 1.3 million

ounces in Inferred, representing a 32% and 74% increase respectively. On an attributable basis (60.3%),

the Gosselin Mineral Resource estimate is 2.7 million ounces Indicated and 1.8 million ounces Inferred.

• Proven and Probable (“P&P”) Mineral Reserves (100% basis) of current assets increased 12% to 11 million

ounces of gold in 302 Mt at 1.14 g/t Au (7.8 million ounces attributable).

- The Westwood Mine Complex (“Westwood”) Mineral Reserves increased 109% to 1.2 million ounces

(5.3 Mt at 7.14 g/t Au), as underground rehabilitation efforts over the course of the year allowed for

the resumption of mining activities in previously closed zones.

• Measured and Indicated (“M&I”) Mineral Resources (100% basis) of current assets increased 16% to 25.9

million ounces of gold in 811.7 Mt at 0.99 g/t Au (18.3 million ounces attributable).

- Côté Gold Project (“Côté Gold” or “Côté”) M&I Mineral Resources (100% basis) increased 1.9 million

ounces or 18% to 12.1 million ounces in 444.8 Mt at 0.84 g/t Au (7.3 million ounce attributable).

• Gold price assumptions for Mineral Reserves were updated to $1,400 per ounce from $1,300 per ounce;

and for Mineral Resources to $1,700 per ounce from $1,500 per ounce.

“The IAMGOLD exploration and operating teams have done an exceptional job over the past year, ensuring that

we have replaced more than we mined during a period when our focus and capital was directed towards the

upcoming ramp up of Côté Gold,” said Renaud Adams, President and Chief Executive Officer of IAMGOLD. “At

Essakane our teams continue to uncover additional value while managing the safety constraints of our operating

footprint, while at Westwood the growth in our reserves is a direct result of the ti reless efforts of our teams and

successes in the extensive redevelopment and rehabilitation of the mine.”

“The updated resource at Gosselin is very exciting as the value of this deposit to the Côté project is clear. Gosselin

is a large-scale deposit sitting immediately adjacent to Côté , that when combined have a n estimated Measured

and Indicated Mineral Resource of 16.5 million ounces with an additional 4.2 million ounces of Inferred, putting

the project in exclusive company of large -scale Canadian assets . This year we look forward to the continued

drilling of Gosselin, targeting the potential connecting extensions of the breccias between the resource pits, as

well drilling beneath the mineralized envelopes to test the depth e xtensions and give some insights into the

ultimate potential of these highly prospective deposits.”

Page | 2 of 11

Mineral Reserves

TABLE 1: MINERAL RESERVES (@100%) SUMMARY

20222 2023 %▲

Tonnes Grade Ounces Tonnes Grade Ounces Tonnes Grade Ounces

(000s) (g/t) (000s) (000s) (g/t) (000s) (000s) (g/t) (000s)

Essakane3

Proven (stockpile) 21,413 0.67 464 20,047 0.65 417 -6% -3% -10%

Probable (open pit) 31,858 1.56 1,597 42,123 1.32 1,787 32% -15% 12%

Total 53,270 1.20 2,061 62,170 1.10 2,204 17% -8% 7%

Westwood4

Proven (underground) 112 11.26 41 382 10.40 128 240% -8% 214%

Probable (underground) 1361 10.83 474 2,982 10.65 1,021 119% -2% 116%

Subtotal 1473 10.86 514 3,364 10.62 1,149 128% -2% 123%

Proven (Grand Duc) 16 1.14 1 465 0.69 10 2807% -39% 900%

Probable (Grand Duc) 1711 1.22 67 1460 1.17 55 -15% -4% -18%

Subtotal 1727 1.22 68 1,925 1.05 65 11% -13% -3%

Total 3,200 5.66 582 5,289 7.14 1,214 65% 26% 109%

Côté Gold3

Proven 130,988 1.01 4,260 132,202 1.09 4,620 1% 8% 8%

Probable 102,343 0.89 2,914 102,442 0.91 2,990 0% 2% 3%

Total 233,331 0.96 7,174 234,644 1.01 7,610 1% 5% 6%

Total P&P Reserves1 289,801 1.05 9,817 302,104 1.14 11,028 4% 9% 12%

1. Figures may not add due to rounding.

2. 2022 Mineral Reserves estimated as of December 31, 2022, using a gold price of $1,300 per ounce for Essakane, Westwood and Cote Gold; and

$1,350 per ounce for the Grand Duc satellite pit at Westwood .

3. 2023 Mineral Reserves estimated as of December 31, 2023, using a gold price of $1,400 per ounce for Essakane and Côté Gold.

4. Westwood (underground) Mineral Reserves have been estimated as of December 31, 2023 using a $1300 per ounce gold price and a 6.41g/t Au cut-

off grade, The Grand Duc Mineral Reserves estimate is included in the Westwood Reserves estimate and have been estimated as of December 31,

2023 using a gold price of $1600 per ounce.

Proven and Probable Mineral Reserves, on a 100% basis for current assets, were estimated at 11.0 million ounces

of gold (7.8 million ounces attributable) as of December 31, 2023, which was a 12% increase or 1.2 million ounces,

from the year prior. Mineral Reserves at Essakane and Westwood increased 143,000 ounces and 6 32,000

ounces, respectively , for a combined 77 5,000 ounces , more than offsetting reserve depletion from mining of

453,000 ounces last year on a 100% basis.

2023 Mineral Reserves Reconciliation (000 oz Au)

1. Mineral Reserves on a 100% basis. Figures may not add due to rounding.

2. Reserve depletion from mining is a subset of depletion from operations based on total material fed to the mill in 2023, containing Mineral Reserves

and Resources, of an estimated 559,000 ounces (11.3 Mt @ 1.26 g/t Au from Essakane and 1.0 Mt @ 3.03 g/t Au from Westwood) .

2 1 1

Page | 3 of 11

Essakane P&P Mineral Reserves, on a 100% basis, increased an estimated 7% from the year prior, to 2.2 million

ounces (2.0 million ounces attributable) at an average grade of 1.10 g/t Au. Probable Mineral Reserves (open pit)

were estimated, on a 100% basis, at 1.8 million ounces (1.6 million ounces attributable) at an average grade of

1.32 g/t Au. On December 18, 2023, IAMGOLD announced an updated Mineral Resource and Reserve estimate

for Essakane that was prepared in accordance with the disclosure requirements of NI 43-101 and had an effective

date of September 30, 2023. Relative to this date, Essakane P&P Mineral Reserves decreased 144,000 ounces

reflective of operating activities conducted in the fourth quarter.

Westwood Mineral Reserves , including the Grand Duc open pit, increased 109% from 582,000 ounces to 1.2

million ounces, net of depletion, with grades increasing 2 6% to 7.14 g/t Au. Excluding Grand Duc, underground

Mineral Reserves were estimated at 1.1 million ounces at an average grade of 10.6 g/t Au. The increase in Mineral

Reserves was driven by the rehabilitation efforts over the course of the year which allowed for the resumption of

mining activities in previously closed zones. The Company plans to file an updated NI 43 -101 technical report in

the second half of the year detailing the results of certain mine optimization efforts and strategic assessments of

the Westwood Complex.

Côté Gold Mineral Reserves , on a 100% basis , increased 6%, or 43 6,000 ounces, to 7.6 million ounces, with

grades increasing 5% to 1.01 g/t Au. On an attributable basis of 60.3% ownership in the joint venture with

Sumitomo Metals Mining Co. Ltd. (“Sumitomo”), Côté Gold Mineral Reserves were estimated at 4.6 million ounces.

The increase in ounces was driven by the increased grade of Proven Mineral Reserves to 1.09 g/t Au based on

an increase in stockpiled inventory and the ongoing grade control drilling program , with minimal impact from the

gold price assumption increase to $1,400 per ounce as the tailings management facility is the primary constraint

on the Mineral Reserves estimate.

A $1,400 per ounce gold price assumption was used in the 2023 Mineral Reserve estimate as of December 31,

2023 for Essakane and Côté Gold , an increase from the prior year assumption of $1,300 per ounce. The

Westwood underground Mineral Reserve gold price assumption was unchanged at $1,300 per ounce.

Mineral Resources

Measured and Indicated Mineral Resources (inclusive of Mineral Reserves and on a 100% basis) for IAMGOLD’s

current assets increased 16% or 3.6 million ounces, to a total of 25.9 million ounces as of December 31, 2023

(18.3 million ounces attributable). M&I Mineral Resource average grades remained essentially flat year over year

at 0.99 g/t Au. The increase in total ounces can be primarily attributed to the increase in M&I Mineral Resources

at Côté Gold and Gosselin.

Global Inferred Mineral Resources (on a 100% basis) declined 10%, or 1.1 million ounces, to a total of 10.1 million

ounces as of December 31, 2023 (7.4 million ounces attributable). The decline in ounces is primarily associated

with the upgrading of resource classification to M&I at Côté Gold, which offset increases at Gosselin, Nelligan and

Essakane. Inferred Mineral Resources have a great amount of uncertainty as to their grade and quantity because

they are based on limited geological evidence. It cannot be assumed that all or part of the Inferred Mineral

Resources will ever be upgraded to a higher category or converted to Mineral Reserves.

The Company assumed a gold price of $1,700 per ounce for estimating Mineral Resources as of December 31,

2023 at Essakane, Côté Gold, Gosselin, Nelligan and Gossey . Westwood Mineral Resources were estimated

using a $1,600 per ounce gold price. Monster Lake and Diakha-Siribaya Mineral Resources were estimated using

a $1,500 per ounce gold price, unchanged from the prior year.

Page | 4 of 11

TABLE 2: MINERAL RESOURCES (@100%) SUMMARY1

20222 20233 %▲

Tonnes Grade Ounces Tonnes Grade Ounces Tonnes Grade Ounces

(000s) (g/t) (000s) (000s) (g/t) (000s) (000s) (g/t) (000s)

OPERATIONS

Essakane

Measured 34,282 0.55 607 21,379 0.64 439 -38% 16% -28%

Indicated 52,945 1.32 2,247 65,702 1.40 2,951 24% 6% 31%

Total M&I 87,227 1.02 2,854 87,081 1.21 3,390 0% 19% 19%

Inferred 2,318 1.44 107 8,344 1.46 392 260% 1% 265%

Westwood4

Measured 791 9.29 236 1,158 7.85 292 46% -15% 24%

Indicated 7,213 8.83 2,047 7,257 9.14 2,133 1% 4% 4%

Total M&I 8,003 8.87 2,283 8,415 8.96 2,425 5% 1% 6%

Inferred 2,699 12.34 1,071 1,465 15.78 743 -46% 28% -31%

Côté Gold

Measured 152,534 0.96 4,726 167,040 0.96 5,160 10% 0% 9%

Indicated 213,382 0.80 5,480 277,733 0.77 6,907 30% -3% 26%

Total M&I 365,916 0.87 10,206 444,773 0.84 12,067 22% -3% 18%

Inferred 189,108 0.63 3,813 60,591 0.61 1,184 -68% -3% -69%

DEVELOPMENT & EXP

Gosselin

Indicated 124,500 0.84 3,350 161,300 0.85 4,420 30% 2% 32%

Inferred 72,900 0.73 1,710 123,900 0.75 2,980 70% 3% 74%

Nelligan7

Indicated 73,500 0.84 1,991 74,500 0.84 2,006 1% 0% 1%

Inferred 129,500 0.87 3,600 142,600 0.85 3,889 10% -2% 8%

Monster Lake5

Inferred 1,110 12.14 433 1,110 12.14 433 0% 0% 0%

Gossey

Indicated 10,454 0.87 291 7,690 0.91 224 -26% 4% -23%

Inferred 2,939 0.91 85 1,520 1.04 51 -48% 15% -40%

Diakha-Siribaya6

Indicated 27,937 1.48 1,325 27,937 1.48 1,325 0% 0% 0%

Inferred 8,468 1.53 417 8,468 1.53 417 0% 0% 0%

Total M&I

Resources1 697,538 0.99 22,300 811,696 0.99 25,858 16% 0% 16%

Total Inferred

Resources1 409,041 0.85 11,237 347,997 0.90 10,090 -15% 6% -10%

1. Figures may not add due to rounding.

2. Mineral Resources estimated as of December 31, 2022, using a gold price of $1,500 per ounce for the Essakane, Westwood (inclu ding Grand Duc

satellite pit), Côté Gold, Gosselin, Nelligan, Monster Lake, Gossey, and Diakha-Siribaya Gold Project.

3. 2023 Mineral Resources estimated as of December 31, 2023, using a gold price of $1,700 per ounce for Essakane, Côté Gold, Gosselin, Nelligan and

Gossey; and have been estimated in accordance with NI 43 -101.

4. Westwood Mineral Resources have been estimated as of December 31, 2023 using a 6.3 0 g/t Au cut-off grade over a minimum width of 2.4 metres,

using a $1,600 per ounce gold price and have been estimated in accordance with NI 43-101. The Grand Duc Mineral Resources and Reserves estimate

is included in the Westwood Mineral Resources and Reserves estimates. The Grand Duc Mineral Resources have been estimated as of December

31, 2023 using a gold price of $1,700 per ounce and have been estimated in accordance with NI 43-101.

5. Monster Lake Mineral Resources have been estimated as of December 31, 2023 using a $1 ,500 per ounce gold price and have been estimated in

accordance with NI 43-101.

6. Diakha-Siribaya Mineral Resources have been estimated as of December 31, 2023 using a $1 ,500 per ounce gold price and have been estimated in

accordance with NI 43-101. On December 20, 2022, IAMGOLD announced that it had entered into definitive agreements to sell the Company's interests

in Diakha-Siribaya. This sale is expected to close in 2024.

7. Nelligan 2022 Mineral Resource estimate announced on January 12, 2023 was amended prior to filing of the Technical Report on February 23, 2023.

The changes resulted to a 21,000 ounce increase in estimated Indicated Mineral Resources and 362,000 ounce increase to Inferred Mineral Resources

due to amendments made to the mining cost applied to waste material and to the percentage of payable metal applied relative to the Mineral Resource

Estimate reported on January 12, 2023.

Page | 5 of 11

Essakane M&I Mineral Resources, inclusive of Mineral Reserves and on a 100% basis, increased 19% to an

estimated 3.4 million ounces (3.1 million ounces attributable) as of December 31, 2023 , with grades increasing

19% to 1.21 g/t Au. Inferred Mineral Resources increased 265% or 285,000 ounces from the year prior with grades

essentially remaining flat at an estimated 1.46 g/t Au. On December 18, 2023, IAMGOLD announced an updated

Mineral Resource and Reserve estimate for Essakane that was prepared in accordance with the disclosure

requirements of NI 43-101 and had an effective date of September 30, 2023. Relative to this date, Essakane M&I

Mineral Resources decreased 127,000 ounces reflective of mining activities conducted in the fourth quarter, while

Inferred Mineral Resources were estimated to be relatively unchanged.

Westwood M&I Mineral Resources, inclusive of Mineral Reserves, increased 6% to 2.4 million ounces as of

December 31, 2023, with a modest increase in grades to 8.9 6 g/t Au. Inferred Mineral Resources declined 31%

to 743,000 ounces as estimated grades increased 28% to 15.78 g/t Au.

Côté Gold M&I Mineral Resources, inclusive of Mineral Reserves and on a 100% basis , increased 18% or 1.9

million ounces, to 12.1 million ounces (7.3 million ounces attributable), with grades decreasing only 3% to 0.84 g/t

Au. Inferred Mineral Resources decreased 69% to 1.2 million ounces at estimated grades of 0.61 g/t Au as a result

of the conversion of Inferred Mineral Resource to Indicated from the ongoing grade control drill programs.

Nelligan M&I Mineral Resources , on a 100% basis, remained relatively flat at an estimated 2 million ounces

averaging 0.84 g/t Au. Inferred ounces increased 8% or 289,000 ounces to a total of an estimated 3.9 million

ounces at average grades of 0.85 g/t Au. On February 13th, 2024, IAMGOLD announced the successful completion

of the previously announced transaction with Vanstar Mining Resources Inc. (“Vanstar”), whereby IAMGOLD has

acquired all of the issued and outstanding common shares of Vanstar pursuant to a court -approved plan of

arrangement. As a result of the Arrangement, IAMGOLD now owns a 100% interest in the Nelligan Gold Project,

located 60 kilometres southwest of Chibougamau, Quebec, Canada.

Gosselin

The Gosselin deposit, located immediately adjacent to the Côté Gold pit, returned an updated Mineral Resource

estimate, on a 100% basis, as of December 31, 2023 of 4.4 million Indicated gold ounces in 161.3 Mt at 0.85 g/t

Au (2.7 million ounces attributable), and 3.0 million Inferred ounces in 123.9 Mt at 0.75 g/t Au (1.8 million ounces

attributable). This represents an estimated increase of 1.1 million ounces in Indicated and 1.3 million ounces in

Inferred, representing a 32% and 74% increase respectively. Combining the Gosselin and Côté deposits together

results in a total Measured and Indicated Mineral Resource estimate for the Côté Gold Project of 16.5 million

ounces with an additional 4.2 million ounces of Inferred.

The Company announced a maiden Mineral Resource estimate for the Gosselin deposit in October 2021 which

incorporated 163 diamond drill holes totalling 54,775 metres. The 2023 updated Mineral Resource estimate

incorporated an additional 57 diamond drill holes totalling 34,790 metres. Drilling to date suggests the Gosselin

deposit has the potential to approach similar dimensions as the adjacent Côté deposit. Drill intercepts obtained

from the newly discovered West Breccia have significantly expanded this breccia body which now measures 250

metres by 170 metres and extends for a depth of approximately 400 metres. This has helped to highlight a highly

prospective corridor at depth measuring u p to 850 metres in strike length that remains to be tested between the

Gosselin West Breccia and the Côté Deposit hydrothermal breccia. This represents a priority exploration

opportunity to further expand the Gosselin resource below the 600 metre vertical depth extent of the current 2023

resources pit shell.

Page | 6 of 11

Figure 1 – Longitudinal section of Côté and Gosselin deposits within Whittle pit shells

TABLE 3: MINERAL RESERVES AND MINERAL RESOURCES AS OF DECEMBER 31, 20231,2,,3

Mineral Resources are inclusive of Mineral Reserves

Page | 7 of 11

Tonnes Grade Ounces Attributable

Ounces

OPERATIONS (000s) (g/t Au) (000s) (000s)

Essakane, Burkina Faso4 [90%]

Proven Mineral Reserves 20,047 0.65 417 375

Probable Mineral Reserves 42,123 1.32 1,787 1,608

Subtotal P&P 62,170 1.1 2,204 1,984

Measured Mineral Resources 21,379 0.64 439 395

Indicated Mineral Resources 65,702 1.40 2,951 2,656

Subtotal M&I (incl. of Reserves) 87,081 1.21 3,390 3,051

Inferred Mineral Resources 8,344 1.46 392 353

Westwood, Canada5 [100%]

Proven Mineral Reserves 847 5.07 138 138

Probable Mineral Reserves 4,443 7.53 1,076 1,076

Subtotal P&P 5,290 7.14 1,214 1,214

Measured Mineral Resources 1,158 7.85 292 292

Indicated Mineral Resources 7,257 9.14 2,133 2,133

Subtotal M&I (incl. of Reserves) 8,415 8.96 2,425 2,425

Inferred Mineral Resources 1,465 15.78 743 743

Côté Gold, Canada7 [60.3%]

Proven Mineral Reserves 132,202 1.09 4,620 2,786

Probable Mineral Reserves 102,442 0.91 2,990 1,803

Subtotal P&P 234,644 1.01 7,610 4,589

Measured Mineral Resources 167,040 0.96 5,160 3,112

Indicated Mineral Resources 277,733 0.77 6,907 4,165

Subtotal M&I (incl. of Reserves) 444,773 0.84 12,067 7,276

Inferred Mineral Resources 60,591 0.61 1,184 714

Gosselin, Canada8 [60.3%]

Indicated Mineral Resources 161,300 0.85 4,420 2,665

Inferred Mineral Resources 123,900 0.75 2,980 1,797

Nelligan, Canada10, 12 [75%]

Indicated Mineral Resources 74,500 0.84 2,006 1,505

Inferred Mineral Resources 142,600 0.85 3,889 2,917

Monster Lake, Canada9 [100%]

Inferred Mineral Resources 1,110 12.14 433 433

Gossey, Burkina Faso6 [90%]

Indicated Mineral Resources 7,690 0.91 224 202

Inferred Mineral Resources 1,520 1.04 51 46

Diakha-Siribaya, Mali11 [90%]

Indicated Mineral Resources 27,937 1.48 1,325 1,193

Inferred Mineral Resources 8,468 1.53 417 376

TOTAL

Tonnes Grade Ounces Attributable

Ounces

(000s) (g/t Au) (000s) (000s)

Proven & Probable Mineral Reserves1 302,103 1.14 11,028 7,786

Measured & Indicated Mineral Resources1 811,696 0.99 25,858 18,317

Inferred Mineral Resources1 347,997 0.90 10,090 7,379

Page | 8 of 11

1. Figures may not add due to rounding.

2. In mining operations, Measured Mineral Resources and Indicated Mineral Resources that are not Mineral Reserves are considered uneconomic at the

price used for Mineral Reserve estimations but are deemed to have a reasonable prospect of economic extraction.

3. See “Cautionary Note to U.S. Investors Regarding Disclosure of Mineral Reserve and Mineral Resource Estimates”.

4. Essakane Mineral Reserves have been estimated as of December 31, 2023 using $1 ,400 per ounce gold price and Mineral Resources have been

estimated as of December 31, 2023 using a $1,700 per ounce gold price and have been estimated in accordance with NI 43 ‐101.

5. Westwood (underground) Mineral Reserves have been estimated as of December 31, 2023 using a $1300 per ounce gold price and a 6.41g/t Au cutoff

grade, and Mineral Resources have been estimated as of December 31, 2023 using a 6.3 0 g/t Au cut ‐off grade over a minimum width of 2.4 metres,

using a $1,600 per ounce gold price and have been estimated in accordance with NI 43‐101. The Grand Duc Mineral Resources and Reserves estimate

is included in the Westwood Mineral Resource s and Reserves estimates. The Grand Du c Mineral Reserves have been estimated as of December 31,

2023 using a gold price of $1 ,600 per ounce and Mineral Resources have been estimated as of December 31, 2023 using a gold price of $1 ,700 per

ounce and have been estimated in accordance with NI 43 ‐101.

6. Gossey Mineral Resources have been estimated as of December 31, 2023 using a $1,700 per ounce gold price and have been estimated in accordance

with NI 43‐101.

7. Côté Gold Mineral Reserves have been estimated as of December 31, 2023 using a $1,400 per ounce gold price and the Mineral Resources have been

estimated as of December 31, 2023 using a $1,700 per ounce gold price and have been estimated in accordance with NI 43 ‐101.

8. Gosselin Mineral Resources have been estimated as of December 31, 2023 using a $1,700 per ounce gold price and have been estimated in accordance

with NI 43‐101.

9. Monster Lake Mineral Resources have been estimated as of December 31, 2023 using a $1 ,500 per ounce gold price and have been estimated in

accordance with NI 43‐101.

10. Nelligan Mineral Resources have been estimated as of December 31, 2023 using a $1,700 per ounce gold price and have been estimated in accordance

with NI 43‐101.

11. Diakha‐Siribaya Mineral Resources have been estimated as of December 31, 2023 using a $1 ,500 per ounce gold price and have been estimated in

accordance with NI 43‐101. On December 20, 2022, IAMGOLD announced that it had entered into definitive agreements to sell the Company’s interests

in Diakha-Siribaya. This sale is expected to close in 2024.

12. Subsequent to the end of the year, o n February 1 3, 2024, IAMGOLD completed the acquisition of Vanstar Resources, increasing the ownership of

Nelligan to 100%.

About IAMGOLD

IAMGOLD is an intermediate gold producer and developer based in Canada with operating mines in North America

and West Africa. The Company is building the large -scale, long life Côté Gold project in Canada in partnership

with Sumitomo Metal Mining Co. Ltd., which is expected to commence production in early 2024. In addition, the

Company has an established portfolio of early stage and advanced exploration projects within high potential

mining districts in Canada. IAMGOLD employs approximately 3, 600 people and is committed to maintaining its

culture of accountable mining through high standards of Environmental, Social and Governance practices,

including its commitment to Zero Harm®, in every aspect of its business. IAMGOLD is listed on the New York

Stock Exchange (NYSE:IAG) and the Toronto Stock Exchange (TSX:IMG) and is one of the companies on the

Jantzi Social Index, a socially screened market capitalization-weighted consisting of companies which pass a set

of broadly based environmental, social and governance rating criteria.

IAMGOLD Contact Information

Graeme Jennings, Vice President, Investor Relations

Tel: 416 360 4743 | Mobile: 416 388 6883

Toll-free: 1 888 464 9999

[email protected]

QUALIFIED PERSON AND TECHNICAL INFORMATION

The Company’s mineral reserves are comprised of in -place material, i.e. material containing ounces of gold for which an

assessment of key modifying factors such as mining, processing, metallurgical recovery, infrastructure, economic, legal,

environmental, social and governmental factors are used to determine their economic viability.

There are numerous parameters inherent in estimating proven mineral reserves and probable mineral reserves, including many

factors beyond the Company’s control. The estimation of mineral reserves is a subjective process, and the accuracy of any

mineral reserves estimate is a function of the quality of available data and of engineering and geological interpretation and

judgment. Results from drilling, testing and production, as well as material changes in metal prices subsequent to the date o f

an estimate, may justify a revision of such estimates.

Lisa Ragsdale, Director, Mining Geology, IAMGOLD Corporation is the “qualified person” for the purposes of NI 43-101 (“QP”)

with respect to the mineralization being reported on and is responsible for the review and approval of all mineral resources

estimates for IAMGOLD. Guy Bourque, Director, Mining, IAMGOLD Corporation is the QP responsible for the review and