  The Gemini Planet Imager (GPI) is a high-contrast imaging instrument designed
to directly image and characterize exoplanets. GPI is currently undergoing
several upgrades to improve performance. In this paper, we discuss the upgrades
to the GPI IFS. This primarily focuses on the design and performance
improvements of new prisms and filters. This includes an improved
high-resolution prism which will provide more evenly dispersed spectra across
y, J, H and K-bands. Additionally, we discuss the design and implementation of
a new low-resolution mode and prism which allow for imaging of all four bands
(y, J, H and K-bands) simultaneously at R=10. We explore the possibility of
using a multiband filter which would block the light between the four spectral
bands. We discuss possible performance improvements from the multiband filter,
if implemented. Finally we explore the possibility of making small changes to
the optical design to improve the IFS's performance near the edge of the field
of view.
