Bryant has one year remaining on his contract.
"He has indicated to me that this is it," Kupchak said Thursday in an interview on SiriusXM NBA Radio, according to ESPN.
Next season will be Bryant's 20th with the Lakers. He is entering the final year of his contract, which will pay him $25 million in 2015-16.
"I think first and foremost, he's on the last year of a deal," Kupchak said, according to ESPN. "There have been no discussions about anything going forward. I don't think there will be."
Bryant hasn't ruled out playing past next season.
Bryant has been limited by injuries each of the last two seasons, only playing six games in 2013-14 and 35 games in 2014-15. His 2012-13 campaign also ended early due to injury.
This season, before a shoulder injury ended his season, he averaged 22.3 points, 5.7 rebounds and 5.6 assists per game while shooting a career-low .373 from the field.
"He's on the last year of his deal," Kupchak told Sirius XM NBA Radio, according to ESPN. "There have been no discussions [about playing beyond next season]. He hasn't indicated that he wants to continue to play."
The Lakers finished 21-61 this season. The Lakers have the No. 2 pick in next month's NBA draft.
- Stanley Kay