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Segments of Business - Reportable operating segment (Details) $ in Millions | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2024 USD ($) segment | Sep. 30, 2023 USD ($) | Sep. 30, 2024 USD ($) segment | Sep. 30, 2023 USD ($) | Mar. 31, 2024 USD ($)
Segment revenues |  |  |  |  |
Total revenues | $ 93,651 | $ 77,215 | $ 172,934 | $ 151,698 |
Segment operating profit (loss) |  |  |  |  |
Total operating profit (loss) | 578 | 951 | 1,607 | 2,051 |
Subtotal | 861 | 1,141 | 2,123 | 2,483 |
Corporate income (expenses), net | (249) | (164) | (352) | (368) |
Interest expense | (78) | (61) | (153) | (108) |
Income before income taxes | 534 | 916 | $ 1,618 | 2,007 |
Number of reportable segments | segment |  |  | 4 |  |
Accounts receivable, credit loss expense (reversal) |  |  | $ (169) | 243 |
Proceeds from legal settlements | 63 |  |  |  |
Pre-tax credits related to LIFO accounting |  |  | (4) | 87 |
Restructuring, impairment, and related charges, net | 234 | 28 | 244 | 80 |
Income (loss) from equity method investments |  |  | (43) |  |
Restructuring charges | 149 | 10 | 148 | 12 |
Canadian businesses held for sale |  |  | 638 | 0 |
Gains (losses) associated with equity investments | (15) | 0 | 95 | 0 |
Canadian retail disposal group | Held-for-sale |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Canadian businesses held for sale | 643 |  | 643 |  |
Strategic Growth Initiative Plan - Operational Efficiencies and Cost Optimization |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Restructuring, impairment, and related charges, net | $ 227 | 3 | 227 | 39 |
Rx Savings Solutions, LLC |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Fair value adjustment gain |  | 48 |  | 76 |
United States |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Number of reportable segments | segment | 3 |  |  |  |
Corporate |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Restructuring, impairment, and related charges, net | $ 23 | 6 | 24 | 46 |
Restructuring charges | 4 | 0 | 3 | 1 |
Gains (losses) associated with equity investments |  |  | 95 |  |
Corporate | Canadian retail disposal group |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Other comprehensive loss | 50 |  | 50 |  |
Corporate | National Prescription Opioid Litigation |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Pre-tax expenses related to estimated litigation liability |  |  | 51 |  |
U.S. Pharmaceutical |  |  |  |  |
Segment revenues |  |  |  |  |
Total revenues | 85,726 | 69,766 | 157,441 | 136,926 |
Segment operating profit (loss) |  |  |  |  |
Total operating profit (loss) | 1,075 | 593 | 1,856 | 1,420 |
Accounts receivable, credit loss expense (reversal) | 203 | 210 | 203 | 210 | $ 725
Proceeds from legal settlements | 63 | 79 | 153 | 197 |
U.S. Pharmaceutical | Operating Segments |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Pre-tax credits related to LIFO accounting | (2) | 55 | (4) | 87 |
Restructuring, impairment, and related charges, net | 64 | 9 | 65 | 11 |
Restructuring charges | 1 | 8 | 1 | 9 |
U.S. Pharmaceutical | Operating Segments | Restructuring Initiatives QTD |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Restructuring, impairment, and related charges, net | 64 |  | 64 |  |
U.S. Pharmaceutical | Operating Segments | National Prescription Opioid Litigation |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Pre-tax expenses related to estimated litigation liability |  |  | 57 |  |
Prescription Technology Solutions |  |  |  |  |
Segment revenues |  |  |  |  |
Total revenues | 1,265 | 1,140 | 2,506 | 2,384 |
Segment operating profit (loss) |  |  |  |  |
Total operating profit (loss) | 205 | 238 | 408 | 469 |
Prescription Technology Solutions | Operating Segments |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Restructuring, impairment, and related charges, net | 1 | 3 | 5 | 5 |
Restructuring charges | 0 | 0 | 0 | 0 |
Medical-Surgical Solutions |  |  |  |  |
Segment revenues |  |  |  |  |
Total revenues | 2,948 | 2,834 | 5,584 | 5,445 |
Segment operating profit (loss) |  |  |  |  |
Total operating profit (loss) | 89 | 244 | 277 | 471 |
Medical-Surgical Solutions | Operating Segments |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Restructuring, impairment, and related charges, net | 147 | 4 | 150 | 6 |
Restructuring charges | 144 | 0 | 144 | 0 |
International |  |  |  |  |
Segment revenues |  |  |  |  |
Total revenues | 3,709 | 3,475 | 7,400 | 6,943 |
Segment operating profit (loss) |  |  |  |  |
Total operating profit (loss) | (508) | 66 | (418) | 123 |
International | Canadian retail disposal group | Held-for-sale |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Canadian businesses held for sale | 593 |  | 593 |  |
International | Operating Segments |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Restructuring, impairment, and related charges, net | (1) | 6 | 0 | 12 |
Restructuring charges | 0 | 2 | 0 | 2 |
Corporate |  |  |  |  |
Segment revenues |  |  |  |  |
Total revenues | $ 3 | $ 0 | $ 3 | $ 0 |
Revenue from Contract with Customer, Product and Service Benchmark | Product Concentration Risk | U.S. Pharmaceutical |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Revenue derived from services, percentage (approximately or less than) | 1.00% |  |  |  |
Revenue from Contract with Customer, Product and Service Benchmark | Product Concentration Risk | Prescription Technology Solutions |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Revenue derived from services, percentage (approximately or less than) | 40.00% |  |  |  |
Revenue from Contract with Customer, Product and Service Benchmark | Product Concentration Risk | Medical-Surgical Solutions |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Revenue derived from services, percentage (approximately or less than) | 1.00% |  |  |  |
Revenue from Contract with Customer, Product and Service Benchmark | Product Concentration Risk | International |  |  |  |  |
Segment operating profit (loss) |  |  |  |  |
Revenue derived from services, percentage (approximately or less than) | 1.00% |  |  |  |

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