I cannot create a summary of the requested article because the article titled "From Equity to Efficiency — Navigating Changes to the AHEAD Model" from the New England Journal of Medicine is not found in the search results provided. The available information about the AHEAD model comes from the CMS website, which states that in September 2025, changes to the AHEAD model were announced to take effect in January 2026. The model covers six states (Maryland, Connecticut, Hawaii, Vermont, Rhode Island, and New York) and will run until December 31, 2035. CMS plans to allow up to two new states to join the model in July 2026. If you have access to the full text article from the New England Journal of Medicine, I can create a detailed summary for you based on its content.