The first season of the show goes out this fall on Sky in a 10 p.M. Slot and on Sky's Now TV streaming service, with Season 2 currently in production.
The comedy follows Daniel Glass (Grint) as a down-on- his-luck insurance rep who is wrongly told he has a terminal illness and decides to keep the misdiagnosis from his family and friends, reported Variety.
Lohan will play Katerina West, the daughter of Glass's boss (Johnson) in the second season, which is expected to bow in 2018.
"Filming for series two is already under way and we're delighted to confirm Lindsay Lohan will be joining Rupert and Nick in this stellar comedy cast."
David Walliams and Miranda Hart's UK production company King Bert are making "Sick Note" for the network.
It is written by Nat Saunders and James Serafinowicz. Sky Vision will sell the comedy internationally.