TransMedics Group, Inc. (TMDX) experienced a significant after-hours plunge of 17.83% following the release of its first-quarter fiscal year 2026 financial results.

The sharp decline came as the company reported adjusted earnings per share of $0.30, which missed analyst estimates of $0.61 by approximately 51%. While quarterly revenue of $173.9 million slightly exceeded expectations, net income plummeted 72% year-over-year to $7.3 million. Operating income also fell sharply by 52% to $13.3 million, and gross margin narrowed to 58% from 61% in the comparable period.

The earnings miss was driven by higher operating expenses, including increased investments in research and development and organizational spending to support growth initiatives. The company reiterated its full-year 2026 revenue guidance of $727 million to $757 million, representing 20% to 25% growth, but investors reacted negatively to the significant profitability compression in the quarter.