{"transactions":[{"id":684665,"issuer":{"id":990,"kind":"organization","name":"Arthur J. Gallagher & Co.","symbol":"AJG"},"owners":[{"id":22596,"kind":"person","name":"Bloom Mark H.","position":1,"cik":"0001795399","reported_name":"Bloom Mark H.","relationship":{"officer":true,"officer_title":"Vice President"}}],"security":"Phantom Stock","published_at":"2026-08-18T23:06:50.000Z","date":"2026-08-16","kind":"exercise","planned":false,"acquired":false,"shares":1280.485,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"Each share of phantom stock represents a right to receive one share of Gallagher common stock."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"These shares represent awards under the Age 62 Plan, a nonqualified deferred compensation plan of the Company, which have been deemed invested in Company common stock at the election of the reporting person.  Participants vest in these awards when they attain age 62, or after a one-year period for participants who have attained age 61."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"These shares represent awards under the Age 62 Plan, a nonqualified deferred compensation plan of the Company, which have been deemed invested in Company common stock at the election of the reporting person.  Participants vest in these awards when they attain age 62, or after a one-year period for participants who have attained age 61."}],"balance_after":6017.051,"derivative":{"underlying":"Common Stock","underlying_shares":1280.485},"source":{"system":"sec-edgar","filing":"0000354190-26-000193","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/354190/000035419026000193/form4.xml","form_type":"4"}},{"id":684664,"issuer":{"id":990,"kind":"organization","name":"Arthur J. Gallagher & Co.","symbol":"AJG"},"owners":[{"id":22596,"kind":"person","name":"Bloom Mark H.","position":1,"cik":"0001795399","reported_name":"Bloom Mark H.","relationship":{"officer":true,"officer_title":"Vice President"}}],"security":"Common Stock","published_at":"2026-08-18T23:06:50.000Z","date":"2026-08-16","kind":"tax_withholding","planned":false,"acquired":false,"shares":606.814,"price":251.21,"value":152437.74494,"ownership":{"direct":true},"balance_after":4416.671,"source":{"system":"sec-edgar","filing":"0000354190-26-000193","document":"form4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/354190/000035419026000193/form4.xml","form_type":"4"}},{"id":684663,"issuer":{"id":990,"kind":"organization","name":"Arthur J. Gallagher & Co.","symbol":"AJG"},"owners":[{"id":22596,"kind":"person","name":"Bloom Mark H.","position":1,"cik":"0001795399","reported_name":"Bloom Mark H.","relationship":{"officer":true,"officer_title":"Vice President"}}],"security":"Common Stock","published_at":"2026-08-18T23:06:50.000Z","date":"2026-08-16","kind":"exercise","planned":false,"acquired":true,"shares":1280.485,"price":0,"value":0.0,"ownership":{"direct":true},"balance_after":5023.485,"source":{"system":"sec-edgar","filing":"0000354190-26-000193","document":"form4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/354190/000035419026000193/form4.xml","form_type":"4"}},{"id":840143,"issuer":{"id":990,"kind":"organization","name":"Arthur J. Gallagher & Co.","symbol":"AJG"},"owners":[{"id":22596,"kind":"person","name":"Bloom Mark H.","position":1,"cik":"0001795399","reported_name":"Bloom Mark H.","relationship":{"officer":true,"officer_title":"Vice President"}}],"security":"Common Stock","published_at":"2026-03-18T01:19:34.000Z","date":"2026-03-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":793,"price":207.93,"value":164888.49,"ownership":{"direct":true},"balance_after":3743,"source":{"system":"sec-edgar","filing":"0000354190-26-000077","document":"form4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/354190/000035419026000077/form4.xml","form_type":"4"}},{"id":840142,"issuer":{"id":990,"kind":"organization","name":"Arthur J. Gallagher & Co.","symbol":"AJG"},"owners":[{"id":22596,"kind":"person","name":"Bloom Mark H.","position":1,"cik":"0001795399","reported_name":"Bloom Mark H.","relationship":{"officer":true,"officer_title":"Vice President"}}],"security":"Common Stock","published_at":"2026-03-18T01:19:34.000Z","date":"2026-03-15","kind":"exercise","planned":false,"acquired":true,"shares":3506,"price":0,"value":0.0,"ownership":{"direct":true},"balance_after":4536,"source":{"system":"sec-edgar","filing":"0000354190-26-000077","document":"form4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/354190/000035419026000077/form4.xml","form_type":"4"}},{"id":840141,"issuer":{"id":990,"kind":"organization","name":"Arthur J. Gallagher & Co.","symbol":"AJG"},"owners":[{"id":22596,"kind":"person","name":"Bloom Mark H.","position":1,"cik":"0001795399","reported_name":"Bloom Mark H.","relationship":{"officer":true,"officer_title":"Vice President"}}],"security":"Common Stock (restricted)","published_at":"2026-03-18T01:19:34.000Z","date":"2026-03-15","kind":"exercise","planned":false,"acquired":false,"shares":3506,"price":0,"value":0.0,"ownership":{"direct":true},"balance_after":0,"source":{"system":"sec-edgar","filing":"0000354190-26-000077","document":"form4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/354190/000035419026000077/form4.xml","form_type":"4"}},{"id":840140,"issuer":{"id":990,"kind":"organization","name":"Arthur J. Gallagher & Co.","symbol":"AJG"},"owners":[{"id":22596,"kind":"person","name":"Bloom Mark H.","position":1,"cik":"0001795399","reported_name":"Bloom Mark H.","relationship":{"officer":true,"officer_title":"Vice President"}}],"security":"Common Stock (restricted)","published_at":"2026-03-18T01:19:34.000Z","date":"2026-03-15","kind":"grant","planned":false,"acquired":true,"shares":3506,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Performance share units (awarded on March 15, 2023) earned and vested as of March 15, 2026."}],"balance_after":3506,"source":{"system":"sec-edgar","filing":"0000354190-26-000077","document":"form4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/354190/000035419026000077/form4.xml","form_type":"4"}},{"id":857232,"issuer":{"id":990,"kind":"organization","name":"Arthur J. Gallagher & Co.","symbol":"AJG"},"owners":[{"id":22596,"kind":"person","name":"Bloom Mark H.","position":1,"cik":"0001795399","reported_name":"Bloom Mark H.","relationship":{"officer":true,"officer_title":"Vice President"}}],"security":"Phantom Stock","published_at":"2026-03-07T01:28:36.000Z","date":"2026-03-04","kind":"grant","planned":false,"acquired":true,"shares":1541.782,"price":227.01,"value":349999.93182,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"Each share of phantom stock represents a right to receive one share of Gallagher common stock."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"These shares represent awards under the Age 62 Plan, a nonqualified deferred compensation plan of the Company, which have been deemed invested in Company common stock at the election of the reporting person.  Participants vest in these awards when they attain age 62, or after a one-year period for participants who have attained age 61."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"These shares represent awards under the Age 62 Plan, a nonqualified deferred compensation plan of the Company, which have been deemed invested in Company common stock at the election of the reporting person.  Participants vest in these awards when they attain age 62, or after a one-year period for participants who have attained age 61."}],"balance_after":7255.745,"derivative":{"underlying":"Common Stock","underlying_shares":1541.782},"source":{"system":"sec-edgar","filing":"0000354190-26-000056","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/354190/000035419026000056/form4.xml","form_type":"4"}},{"id":871927,"issuer":{"id":990,"kind":"organization","name":"Arthur J. Gallagher & Co.","symbol":"AJG"},"owners":[{"id":22596,"kind":"person","name":"Bloom Mark H.","position":1,"cik":"0001795399","reported_name":"Bloom Mark H.","relationship":{"officer":true,"officer_title":"Vice President"}}],"security":"Non-qualified Stock Option","published_at":"2026-03-03T23:44:33.000Z","date":"2026-03-01","kind":"grant","planned":false,"acquired":true,"shares":13331,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"One-third of this stock option becomes exercisable on each of the 3rd, 4th, and 5th anniversaries of the grant date."}],"balance_after":13331,"derivative":{"exercise_price":228.2,"expiration_date":"2033-03-01","underlying":"Common Stock","underlying_shares":13331},"source":{"system":"sec-edgar","filing":"0000354190-26-000018","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/354190/000035419026000018/form4.xml","form_type":"4"}},{"id":1213819,"issuer":{"id":990,"kind":"organization","name":"Arthur J. Gallagher & Co.","symbol":"AJG"},"owners":[{"id":22596,"kind":"person","name":"Bloom Mark H.","position":1,"cik":"0001795399","reported_name":"Bloom Mark H.","relationship":{"officer":true,"officer_title":"Vice President"}}],"security":"Phantom Stock","published_at":"2025-03-12T00:33:00.000Z","date":"2025-03-10","kind":"other","planned":false,"acquired":true,"shares":778.259,"price":321.23,"value":250000.13857,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"Each share of phantom stock represents a right to receive one share of Gallagher common stock."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"These shares represent awards under the Age 62 Plan, a nonqualified deferred compensation plan of the Company, which have been deemed invested in Company common stock at the election of the reporting person.  Participants vest in these awards when they attain age 62, or after a one-year period for participants who have attained age 61."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"These shares represent awards under the Age 62 Plan, a nonqualified deferred compensation plan of the Company, which have been deemed invested in Company common stock at the election of the reporting person.  Participants vest in these awards when they attain age 62, or after a one-year period for participants who have attained age 61."}],"balance_after":5667.421,"derivative":{"underlying":"Common Stock","underlying_shares":778.259},"source":{"system":"sec-edgar","filing":"0001127602-25-009171","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/354190/000112760225009171/form4.xml","form_type":"4"}},{"id":1224860,"issuer":{"id":990,"kind":"organization","name":"Arthur J. Gallagher & Co.","symbol":"AJG"},"owners":[{"id":22596,"kind":"person","name":"Bloom Mark H.","position":1,"cik":"0001795399","reported_name":"Bloom Mark H.","relationship":{"officer":true,"officer_title":"Vice President"}}],"security":"Non-qualified Stock Option","published_at":"2025-03-06T02:25:02.000Z","date":"2025-03-01","kind":"grant","planned":false,"acquired":true,"shares":6887,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"Closing price of Gallagher common stock on February 28, 2025."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"One-third of this stock option becomes exerciseable on each of the 3rd, 4th, and 5th anniversaries of the grant date."}],"balance_after":6887,"derivative":{"exercise_price":337.74,"expiration_date":"2032-03-01","underlying":"Common Stock","underlying_shares":6887},"source":{"system":"sec-edgar","filing":"0001127602-25-008472","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/354190/000112760225008472/form4.xml","form_type":"4"}},{"id":1600589,"issuer":{"id":990,"kind":"organization","name":"Arthur J. Gallagher & Co.","symbol":"AJG"},"owners":[{"id":22596,"kind":"person","name":"Bloom Mark H.","position":1,"cik":"0001795399","reported_name":"Bloom Mark H.","relationship":{"officer":true,"officer_title":"Vice President"}}],"security":"Phantom Stock","published_at":"2024-03-05T23:51:57.000Z","date":"2024-03-04","kind":"other","planned":false,"acquired":true,"shares":1028.26,"price":243.13,"value":250000.8538,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Each share of phantom stock represents a right to receive one share of Gallagher common stock."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"These shares represent awards under the Age 62 Plan, a nonqualified deferred compensation plan of the Company, which have been deemed invested in Company common stock at the election of the reporting person.  Participants vest in these awards when they attain age 62, or after a one-year period for participants who have attained age 61."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F3","text":"These shares represent awards under the Age 62 Plan, a nonqualified deferred compensation plan of the Company, which have been deemed invested in Company common stock at the election of the reporting person.  Participants vest in these awards when they attain age 62, or after a one-year period for participants who have attained age 61."}],"balance_after":4670.666,"derivative":{"underlying":"Common Stock","underlying_shares":1028.26},"source":{"system":"sec-edgar","filing":"0001127602-24-008714","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/354190/000112760224008714/form4.xml","form_type":"4"}},{"id":1600588,"issuer":{"id":990,"kind":"organization","name":"Arthur J. Gallagher & Co.","symbol":"AJG"},"owners":[{"id":22596,"kind":"person","name":"Bloom Mark H.","position":1,"cik":"0001795399","reported_name":"Bloom Mark H.","relationship":{"officer":true,"officer_title":"Vice President"}}],"security":"Non-qualified Stock Option","published_at":"2024-03-05T23:51:57.000Z","date":"2024-03-01","kind":"grant","planned":false,"acquired":true,"shares":5777,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"One-third of this stock option becomes exercisable on each of the 3rd, 4th, and 5th anniversaries of the grant date."}],"balance_after":5777,"derivative":{"exercise_price":243.54,"expiration_date":"2031-03-01","underlying":"Common Stock","underlying_shares":5777},"source":{"system":"sec-edgar","filing":"0001127602-24-008714","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/354190/000112760224008714/form4.xml","form_type":"4"}},{"id":1948963,"issuer":{"id":990,"kind":"organization","name":"Arthur J. Gallagher & Co.","symbol":"AJG"},"owners":[{"id":22596,"kind":"person","name":"Bloom Mark H.","position":1,"cik":"0001795399","reported_name":"Bloom Mark H.","relationship":{"officer":true,"officer_title":"Vice President"}}],"security":"Non-qualified Stock Option","published_at":"2023-03-17T23:44:59.000Z","date":"2023-03-15","kind":"grant","acquired":true,"shares":4673,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"One-third of this stock option becomes exerciseable on each of the 3rd, 4th, and 5th anniversaries of the grant date."}],"balance_after":4673,"derivative":{"exercise_price":177.09,"expiration_date":"2030-03-15","underlying":"Common Stock","underlying_shares":4673},"source":{"system":"sec-edgar","filing":"0001127602-23-010770","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/354190/000112760223010770/form4.xml","form_type":"4"}},{"id":1955761,"issuer":{"id":990,"kind":"organization","name":"Arthur J. Gallagher & Co.","symbol":"AJG"},"owners":[{"id":22596,"kind":"person","name":"Bloom Mark H.","position":1,"cik":"0001795399","reported_name":"Bloom Mark H.","relationship":{"officer":true,"officer_title":"Vice President"}}],"security":"Phantom Stock","published_at":"2023-03-15T01:32:19.000Z","date":"2023-03-10","kind":"other","acquired":true,"shares":2016.7,"price":185.95,"value":375005.365,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"Each share of phantom stock represents a right to receive one share of Gallagher common stock."},{"field":"shares","element":"transactionShares","label":"F2","text":"These shares represent awards under the Age 62 Plan, a nonqualified deferred compensation plan of the Company, which have been deemed invested in Company common stock at the election of the reporting person.  Participants vest in these awards when they attain age 62, or after a one-year period for participants who have attained age 61."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"These shares represent awards under the Age 62 Plan, a nonqualified deferred compensation plan of the Company, which have been deemed invested in Company common stock at the election of the reporting person.  Participants vest in these awards when they attain age 62, or after a one-year period for participants who have attained age 61."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"These shares represent awards under the Age 62 Plan, a nonqualified deferred compensation plan of the Company, which have been deemed invested in Company common stock at the election of the reporting person.  Participants vest in these awards when they attain age 62, or after a one-year period for participants who have attained age 61."}],"balance_after":3610.879,"derivative":{"underlying":"Common Stock","underlying_shares":2016.7},"source":{"system":"sec-edgar","filing":"0001127602-23-010202","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/354190/000112760223010202/form4.xml","form_type":"4"}}]}