First Majestic Reports High-Grade Drill Results and Expands Exploration Footprint at San Dimas

Resource-conversion and resource-addition drilling returned multiple high-grade silver and gold intercepts across the San Dimas district

New drilling results at Convención and El Cristo have expanded the exploration footprint and support the potential for future Mineral Resource growth

Vancouver, BC, Canada, September 9, 2026 - First Majestic Silver Corp. (NYSE:AG) (TSX:AG) (FSE:FMV) (the “Company” or “First Majestic”) is pleased to announce positive drill results from its ongoing 2026 exploration program at its San Dimas Silver/Gold Mine in Durango, Mexico. Recent resource-conversion and resource-addition drilling has returned multiple high-grade silver and gold intercepts across several areas of the San Dimas district, supporting near-mine Mineral Resource conversion and growth opportunities. Additionally, new drill results at Convención and El Cristo have expanded the district’s exploration footprint and identified additional targets for follow-up drilling as part of the Company’s 2026 exploration program, which includes approximately 117,000 metres (“m”) of planned drilling.

“San Dimas continues to validate its position as one of our most prospective and enduring mining districts,” stated Keith Neumeyer, CEO of First Majestic. “The latest drill results have returned multiple high-grade silver and gold intercepts from both resource-conversion and resource-addition programs, reinforcing the near-mine growth potential of established vein systems while expanding the exploration footprint at Convención and El Cristo. With approximately 117,000 metres of drilling planned in 2026, we are advancing one of the Company’s largest exploration programs, focused on Mineral Resource conversion, testing new targets and identifying additional growth opportunities throughout the San Dimas district.”

KEY DRILLING HIGHLIGHTS

Exploration drilling at San Dimas has intersected significant silver (“Ag”) and gold (“Au”) mineralization across multiple vein systems, supporting both near-mine Mineral Resource conversion and broader district exploration opportunities. A total of approximately 89,000 m of exploration drilling has been completed year-to-date in 2026, of the planned approximately 117,000 m program, with work focused on resource-conversion and resource-addition drilling in the West Block, Central Block and Graben block, together with follow-up drilling in the El Cristo mine area and continued target testing in the East/Arana Block.

Recent results include high-grade intercepts from resource-conversion and resource-addition drilling within the Sinaloa–Elia vein complex, continued expansion of the mineralized footprint at the Coronado–Carmen Escobosa vein system in the West Block, confirmation of a new target north of the Jessica vein at Convención, and encouraging early results from the Luz and Patricia veins within the El Cristo mine area. Selected significant intercepts are summarized in Table 1, and the principal target areas are shown in Figure 1.

Table 1: Selection of Significant Silver and Gold Drill Hole Intersections from the San Dimas 2026 Drill Program

Figure 1: San Dimas District Vein Occurrence Map

Sinaloa–Elia Vein Complex

Resource-addition and infill drilling at the historic Sinaloa–Elia vein complex has returned multiple high-grade silver and gold intercepts, further supporting the continuity and Mineral Resource growth potential of the system. New drill results extend the footprint of known mineralization beyond the current Mineral Resources to the east, west and locally down dip. Infill drilling has also returned thick, high-grade intercepts that support increased confidence in the mineralized system and the potential conversion of Inferred Mineral Resources to Indicated Mineral Resources, providing additional support for future mine planning (Figure 2).

Table 2: Selection of Significant Silver and Gold Drill Hole Intersections at the Sinaloa-Elia Vein Complex

Figure 2: Sinaloa and Elia Veins, Vertical Long Section, Looking North

Convención Vein

Geological analysis and targeting around the Jessica vein identified several historic anomalous vein and breccia intercepts that were reinterpreted as evidence for the presence of a hanging wall structure. Initial drill testing of this target returned five significant intercepts in seven holes, supporting the exploration hypothesis (Figure 3). The structure, the Convención vein, was intersected approximately 100 m north of Jessica and may represent a potential near-term mining opportunity. The target vein remains open in multiple directions, supporting additional follow-up drilling in the area (Figure 4).

Table 3: Selection of Significant Silver and Gold Drill Hole Intersections at the Convención Vein

Figure 3: Santa Jessica Vein and New Convención Vein Geologic Interpretation, 1050 Level Plan, Looking Down

Figure 4: Convención Long Section with Santa Jessica Historic Mining Footprint Shown for Reference, Looking North

Coronado – Carmen Escobosa Complex

Drilling in the West Block has focused on the Coronado and Carmen Escobosa veins. Results from 2025 were incorporated into the Inferred Mineral Resources for San Dimas and provided the basis for follow-up drilling in 2026. Results received to date support the interpretation of Coronado and Carmen Escobosa as a two-vein mineralized system with continued potential for Mineral Resource addition (Figure 5).

At Carmen Escobosa, five drill holes testing the western continuity of mineralization, together with a drill hole targeting the eastern extension, returned significant intercepts. The target remains open for approximately 400 m to the west of these new intercepts, supporting additional follow-up drilling along strike (Figure 6). At Coronado, three drill holes testing the continuity of mineralization to the west also returned significant intercepts, further supporting the potential to expand the mineralized footprint in the West Block (Figure 7).

Table 4: Selection of Significant Silver and Gold Drill Hole Intersections at the Coronado – Carmen Escobosa Complex

Figure 5: Coronado and Carmen Escobosa Geologic Model, 700 Level Plan, Looking Down

Figure 6: Carmen Escobosa Long Section, Looking North

Figure 7: Coronado Long Section, Looking North

El Cristo Mine

Exploration activities have expanded to include the El Cristo mine area, the southernmost historically mined areas on the property. Results to date have returned high-grade silver and gold intercepts from the Luz and Patricia veins, supporting follow-up drilling to evaluate the continuity and extent of mineralization. Select drill hole assay results and true-width vein intersections include:

Table 5: Selection of Significant Silver and Gold Drill Hole Intersections at the El Cristo Mine

Figure 8: El Cristo Mine Area, La Luz Vein Long Section, Looking Northwest

The 2026 drill program at San Dimas is expected to continue advancing near-mine Mineral Resource conversion while testing additional targets across the district. Results received to date support the potential for Mineral Resource growth within established vein systems and highlight new opportunities at Convención and El Cristo for follow-up drilling.

Table 6: Selection of Significant Silver and Gold Drill Hole Intercepts at San Dimas

Notes:

1. All holes are Diamond Drill Core; AgEq grade = Ag grade (g/t) + [Au (g/t) * 75].
2. From and To length indicated in metres, True Width of the intercept is calculated per drill hole and vein angles.
3. See Appendix to this news release for details regarding drill hole locations, sample type, azimuth, dip and total depth.
4. San Dimas: silver and gold drill hole significant intercepts were composited using the length weighted averages of uncapped sample assays, a 171g/t AgEq minimum grade (cut-off grade, “COG”), and a minimum composite length of 0.7 m (true width). A maximum of 1 m below the minimum COG was allowed as internal dilution. Where necessary to achieve minimum length, a single sample below the COG but grading >70g/t AgEq was allowed to be composited for short intervals.
5. Where present, single samples or intercepts with assay results higher than 1000 g/t AgEq are highlighted as “Include” in each intercept.

First Majestic’s drill programs follow established Quality Assurance/Quality Control (“QA/QC”) protocols with standards, blanks, and duplicates inserted into the sample stream. After geological logging, all drill core samples are cut in half. One half of the core is submitted to the laboratory for analysis, and the remaining half core is retained on-site for verification and reference purposes or future metallurgical testing.

Core samples are submitted to First Majestic’s Central Laboratory (“Central Laboratory”) (ISO 9001:2015). At the Central Laboratory, gold is analyzed by 30 g fire assay atomic absorption finish (AU-AA13). Results above 10 g/t gold are re-analyzed by 30 g fire assay gravimetric finish (ASAG-14). Silver is analyzed by 3-acid digestion atomic absorption finish (AAG-13). Results above 100 g/t silver are re-analyzed by 30 g fire assay gravimetric finish (ASAG-14, ASAG-13).

For further information concerning QA/QC and data verification matters, key assumptions, parameters, and methods used by the Company to estimate Mineral Reserves and Mineral Resources, and for a detailed description of known legal, political, environmental, and other risks that could materially affect the Company’s business and the potential development of Mineral Reserves and Mineral Resources, see the Company’s most recently filed Annual Information Form available under the Company’s SEDAR+ profile at www.sedarplus.ca and the Company's most recently filed Annual Report on Form 40-F, available on the Company’s website at www.firstmajestic.com and filed with the United States Securities and Exchange Commission on EDGAR at www.sec.gov/edgar.

QUALIFIED PERSONS

Gonzalo Mercado, P. Geo., the Company’s Vice-President of Exploration and Technical Services and a “Qualified Person” as defined under National Instrument 43-101 Standards of Disclosure for Mineral Projects (“NI 43-101”), has reviewed and approved the scientific and technical information contained in this news release. Mr. Mercado has verified the exploration data contained in this news release, including the sampling, analytical, and test data underlying such information.

ABOUT FIRST MAJESTIC

First Majestic is a publicly traded mining company focused on silver and gold production in Mexico and the United States. The Company presently owns and operates four producing underground mines in Mexico: the Santa Elena Silver/Gold Mine, the Los Gatos Silver Mine (the Company holds a 70% interest in the Los Gatos Joint Venture that owns and operates the mine), the San Dimas Silver/Gold Mine, and the La Encantada Silver Mine, as well as a portfolio of development and exploration assets, including the Jerritt Canyon Gold Mine located in northeastern Nevada, U.S.A, which the Company is currently in the process of re-starting.

First Majestic is proud to own and operate its own minting facility, First Mint, LLC, and to offer a portion of its silver production for sale to the public. Bars, ingots, coins, and medallions are available for purchase online at www.firstmint.com, at some of the lowest premiums available.

For further information, contact info@firstmajestic.com visit our website at www.firstmajestic.com or call our toll-free number 1.866.529.2807.

FIRST MAJESTIC SILVER CORP.

"signed"

Keith Neumeyer, CEO

Cautionary Note Regarding Forward Looking Statements

This news release contains “forward‐looking information” and “forward-looking statements” under applicable Canadian and U.S. securities laws (collectively, “forward‐looking statements”). These statements relate to future events or the Company’s future performance, business prospects or opportunities that are based on forecasts of future results, estimates of amounts not yet determinable and assumptions of management made in light of management’s experience and perception of historical trends. Forward-looking statements in this news release include but are not limited to statements with respect to: the total number of metres planned to be drilled at San Dimas in 2026; the potential for future Mineral Resource growth at San Dimas; the potential for the Convención vein to represent a near-term mining opportunity at San Dimas; and the Company’s plans for the remainder of the 2026 drill program at San Dimas and the results of such program. Assumptions may prove to be incorrect and actual results and future events may differ materially from those anticipated. As such, investors are cautioned not to place undue reliance upon forward-looking statements as there can be no assurance that the plans, assumptions, or expectations upon which they are placed will occur. Any statements that express or involve discussions with respect to predictions, expectations, beliefs, plans, projections, objectives or future events or performance (often, but not always, using words or phrases such as “seek”, “anticipate”, “plan”, “continue”, “estimate”, “expect”, “may”, “will”, “project”, “predict”, “forecast”, “potential”, “target”, “intend”, “could”, “might”, “should”, “believe” and similar expressions) are not statements of historical fact and may be "forward‐looking statements".

Actual results may vary from forward-looking statements. Forward-looking statements are subject to known and unknown risks, uncertainties and other factors that may cause actual results to materially differ from those expressed or implied by such forward-looking statements, including but not limited to: material adverse changes; general economic conditions including inflation risks; labour relations; relations with local communities; changes in national or local governments; exchange rate fluctuations; environmental risks; requirements for additional capital; outcomes of pending litigation; unexpected changes in laws, rules or regulations, or their enforcement by applicable authorities; the failure of parties to contracts with the Company to perform as agreed; social or labour unrest; changes in commodity prices; and the failure of exploration programs or studies to deliver anticipated results or results that would justify and support continued exploration, studies, development or operations as well as those factors discussed in the section entitled “Risk Factors” in the Company’s most recent Annual Information Form for the year ended December 31, 2025 filed with the Canadian securities regulatory authorities under the Company’s SEDAR+ profile at www.sedarplus.ca and in the Company’s Annual Report on Form 40-F for the year ended December 31, 2025 filed with the United States Securities and Exchange Commission on EDGAR at www.sec.gov/edgar. Although the Company has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking statements, there may be other factors that cause results not to be as anticipated, estimated, or intended.

The Company believes that the expectations reflected in these forward‐looking statements are reasonable, but no assurance can be given that these expectations will prove to be correct and such forward‐looking statements included herein should not be unduly relied upon. These statements speak only as of the date hereof. The Company does not intend, and does not assume any obligation, to update these forward-looking statements, except as required by applicable laws.

Cautionary Note to United States Investors

The Company is a “foreign private issuer” as defined in Rule 3b-4 under the United States Securities Exchange Act of 1934, as amended, and is eligible to rely upon the Canada-U.S. Multi-Jurisdictional Disclosure System, and is therefore permitted to prepare the technical information contained herein in accordance with the requirements of the securities laws in effect in Canada, which differ from the requirements of the securities laws currently in effect in the United States. Accordingly, information concerning mineral deposits set forth herein may not be comparable with information made public by companies that report in accordance with U.S. standards.

Technical disclosure contained in this news release has not been prepared in accordance with the requirements of United States securities laws and uses terms that comply with reporting standards in Canada with certain estimates prepared in accordance with NI 43-101.

NI 43-101 is a rule developed by the Canadian Securities Administrators that establishes standards for all public disclosure an issuer makes of scientific and technical information concerning the issuer's material mineral projects.

APPENDIX – DRILL HOLE DETAILS

Table A1: Drill hole collar location, sample type, azimuth, dip and total depth.

Notes:

1. All drill hole collar coordinates are determined using total station equipment after hole completion with UTM WGS84, Zone 13 (metres) as the reference system.