The American squad have struggled this year and sit ninth in the constructors' championship.
Despite several impressive qualifying performances, the VF-19's race pace has been found wanting time and time again, with Haas at a loss to explain their issues. As such, Grosjean has scored just eight points across three top-10 finishes.
It had led to suggestions that Hulkenberg may be drafted in following confirmation of his release from Renault, but Haas have decided to stick with their current line-up.
Haas team principal Guenther Steiner said: "Experience, and the need for it, has been one of the cornerstones of Haas F1 Team, and with Romain Grosjean and Kevin Magnussen racing for the team in 2020, we continue to have a driver lineup that offers us a solid platform to continue our growth.
"Their understanding of how we work as a team, and our knowledge of what they can deliver behind the wheel, gives us a valued continuity and a strong foundation to keep building our team around.
"It’s been a tough year for us in 2019 with the fluctuation in performance of the VF-19, but our ability to tap into our combined experiences will help us learn, improve, and move forward as a unit in 2020."
Hulkenberg has been tentatively linked to Red Bull as well as Haas and recently suggested that he would have a race seat in 2020.
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