Piotr Swat | SOPA Images | Lightrocket | Getty Images Major health insurers appear to be off to an encouraging start this year — but a crucial test for the sector is still ahead. Solid first-quarter results have helped lift investor sentiment, even as insurers continue to grapple with higher medical costs. Companies including UnitedHealth , Elevance , Cigna and Humana all beat estimates for the quarter, with some hiking their 2026 outlooks.  Those results were largely expected due to seasonal factors such as a milder flu season and weather disruptions that temporarily suppressed medical costs, said Barclays analyst Andrew Mok. A more meaningful signal, Mok said, is that insurers strengthened medical reserves — money set aside to pay future claims — adding a cushion that could support their outlooks. But there's still a "huge caveat," according to Baird analyst Michael Ha.…