Centene founded Sep 1984 as Family Hospital Physicians Centers — Wisconsin Medicaid managed care startup founded by Elizabeth 'Betty' Brinn; renamed Centene Corp 1997 under Michael Neidorff. Pioneers Medicaid managed care — government-paid health plans for low-income enrollees. Defines new US managed care vertical.

Michael Neidorff becomes Centene CEO 1996 (until Apr 2022) — transforms small Wisconsin Medicaid HMO into national managed care leader. Centene IPO Dec 2001 at $7.50/share. Stock 100x's by 2017 making Neidorff one of the most successful health insurance CEOs ever.

Centene IPO Dec 2001 on NYSE at $7.50/share. Michael Neidorff CEO; transforms small Wisconsin Medicaid HMO into national leader. Stock 100x's by 2017 making CNC one of best-performing health insurance stocks ever. Neidorff dies Apr 2022 at 79.

Centene acquires Health Net Mar 2016 for $6.8B all-stock — expands into West Coast Medicaid + Tricare military health. First major Centene transformative acquisition; sets template for $100B+ revenue ambition. Combined entity becomes top-10 US health insurer.

Centene acquires WellCare Jan 2020 for $17.3B cash + stock — combines #1 Medicaid managed care company (Centene) + #5 (WellCare). Triples MA membership. CEO Michael Neidorff's last major acquisition. Combined entity serves 25M+ Medicaid members making CNC largest US Medicaid managed care insurer.

Sarah London becomes Centene CEO Apr 2022 succeeding Michael Neidorff (who died Apr 2022 at 79). London inherits sprawling 100+ subsidiary Centene with PBM scandals + state Medicaid contract overcharge settlements ($1.5B+ aggregate). Executes massive divestment + simplification 2022-2024.

Centene CEO Sarah London (since Mar 2022) executes massive divestment program 2022-2023 selling international operations (Australia, UK, Spain), pharmacy benefits (Magellan Rx), specialty businesses to focus on US Medicaid + Medicare + ACA marketplace. Stock recovers from $48 (Feb 2023 trough) to $75+ Q1 2024.

Centene FY2024 — Sarah London CEO reports $164B revenue; serves 28M+ members across Medicaid + ACA + Medicare. Medicaid redetermination headwinds 2023-2024 + ACA enrollment growth partially offset. Stock $58 (recovered from $48 Feb 2023 trough) but still below $100 2022 peak.

Centene Q3 2025 — Sarah London CEO continues Medicaid redetermination headwinds; medical loss ratio (MLR) 90%+ pressures earnings. Centene Mexico exit completed; final international divestiture. Stock $65 vs 2023 $48 trough. Centene serves 13M+ Medicaid members making it largest US Medicaid managed care insurer.