Hologic CEO Stephen MacMillan to Retire as $14.8B Private Equity Deal Nears Close
Hologic Inc. (NASDAQ: HOLX) announced today that President and Chief Executive Officer Stephen P. MacMillan will retire from his leadership positions immediately following the completion of the company's $14.8 billion acquisition by private equity firms Blackstone Inc. and TPG Global, LLC.
The Change
MacMillan informed Hologic's Board of Directors on April 6, 2026, of his decision to retire as both CEO and Chairman of the Board, with the retirement taking effect immediately after the merger closes. The transaction, first announced in October 2025, has received all necessary regulatory approvals and is expected to close on or about April 7, 2026.
The timing of MacMillan's departure coincides with the company's transition from public to private ownership, marking the end of an era for the medical technology company that has been publicly traded since its initial public offering. The retirement announcement comes as part of the formal 8-K filing with the Securities and Exchange Commission, confirming that MacMillan's exit is contingent upon and will occur simultaneously with the merger's completion.
Background
Stephen MacMillan has served as Hologic's President and CEO since December 2013, leading the company through a significant transformation period. Under his leadership, Hologic evolved from a company primarily focused on mammography and women's health diagnostics into a diversified medical technology leader with expanded offerings in molecular diagnostics, surgical products, and breast health solutions.
During MacMillan's tenure, Hologic navigated numerous challenges including the COVID-19 pandemic, during which the company's molecular diagnostics division played a crucial role in developing and manufacturing COVID-19 tests. The company's stock price appreciated significantly under his leadership, ultimately attracting the attention of private equity buyers Blackstone and TPG, who agreed to acquire Hologic for approximately $14.8 billion in October 2025.
Prior to joining Hologic, MacMillan held leadership positions at several major medical device companies, bringing decades of industry experience to his role. His decision to retire at the point of the private equity transition follows a common pattern in take-private transactions, where existing leadership often departs to make way for new management teams selected by the acquiring firms.
What It Means
MacMillan's retirement signals the beginning of a new chapter for Hologic under private equity ownership. Blackstone and TPG will likely install new leadership aligned with their strategic vision for the company, which may include operational improvements, portfolio optimization, or preparing certain divisions for eventual sale or spin-off.
For Hologic's approximately 6,000 employees, the leadership transition could bring changes in corporate strategy and culture. Private equity owners typically focus on improving operational efficiency and driving growth through both organic initiatives and acquisitions, potentially leading to restructuring efforts or strategic shifts in the company's product portfolio.
The filing does not identify MacMillan's successor, suggesting that Blackstone and TPG may still be finalizing their leadership plans for the company. The new CEO will inherit a company with strong positions in breast health, diagnostics, and gynecological surgical products, but will also face the challenge of managing the company under the financial constraints and return expectations typical of private equity ownership.
Investors holding Hologic shares will receive cash consideration once the merger closes, ending their equity participation in the company's future performance. The transaction includes contingent value rights (CVRs) that could provide additional payments to shareholders based on certain future milestones, though the filing notes that CVR holders may receive "less-than-anticipated payments" depending on how events unfold.
The successful completion of all regulatory approvals removes the last major hurdle to closing the transaction, making MacMillan's departure and the ownership transition essentially certain within the next few days.