Tempus AI to Buy Personalis, Enters MRD Market as Growth Slows
Tempus AI agreed to acquire Personalis for $16.25 a share as its own revenue growth decelerated to 36.1% in the first quarter from 83% at the end of 2025.
Tempus AI (TEM) agreed to acquire Personalis in a roughly $1.5 billion, all-stock deal priced at $16.25 a share, with a cash option capped at 50% of consideration, giving the precision-medicine data company entry into the roughly $20 billion minimal residual disease monitoring market.
The deal arrives as Tempus AI's own growth engine cooled. Revenue rose 83.0% year over year to $367.2 million in the fourth quarter of 2025; in the first quarter of 2026 that growth rate fell to 36.1%, with revenue of $348.1 million marking a sequential decline as well. The deceleration traced largely to the Diagnostics segment, where year-over-year growth dropped to 34.7% in the first quarter from 121.6% in the fourth quarter of 2025, as the company lapped its Ambry acquisition.
Data and Applications moved the other direction. Revenue there grew 40.5% year over year in the first quarter, up from 25.1% in the fourth quarter of 2025, though the Insights product line's growth slowed to 44.1% from 69.5% over the same span.
Profitability swung negative. Adjusted EBITDA fell to a loss of $2.8 million in the first quarter from a positive $12.9 million in the fourth quarter of 2025, and net loss widened to $125.9 million from $54.2 million in the prior quarter and $68.0 million a year earlier, an 85.1% year-over-year increase. Part of the widening was due to $56.3 million in stock-based compensation and $32.3 million in unrealized losses on securities. Cash and marketable securities fell to $643.8 million at the end of the first quarter from $759.7 million at year-end 2025.
The Personalis transaction is designed to accelerate the part of the business still expanding. Tempus AI's own MRD test volume climbed to about 6,500 tests in the first quarter of 2026, up 500% year over year and 38% from roughly 4,700 tests in the fourth quarter of 2025. Personalis reported preliminary second-quarter 2026 revenue of $22.4 million on 10,384 clinical tests, up 33% quarter over quarter, a volume base Tempus AI would add on top of its own MRD ramp.
Despite the first-quarter deceleration, Tempus AI raised its full-year 2026 revenue guidance modestly, to a range of $1.59 billion to $1.60 billion from the $1.59 billion figure given alongside fourth-quarter results, while holding full-year Adjusted EBITDA guidance at roughly $65 million. Final 2025 results came in slightly ahead of the company's preliminary estimate, with revenue of $1.3 billion representing 83.4% growth versus the roughly 83% preliminary figure disclosed earlier.
The Personalis deal follows a $350.0 million convertible notes offering due 2032 that Tempus AI closed in the prior quarter, proceeds of which were used to repay $307.7 million of senior secured credit facility debt and fund capped call transactions. Together, the moves show a company financing an acquisition-led push into a new diagnostic category even as its core revenue growth rate has been cut by more than half over two quarters.