Melissa Lee has been demoted out of Cabinet, the Prime Minister has announced in a statement on Wednesday afternoon.
He said the move comes as the media sector faces "significant challenges". Lee was until Wednesday the Media and Communications Minister. She received criticism for her response to the proposed closure of Newshub.
Luxon also said Penny Simmonds would be taken out of the Minister for Disability Issues role to free her up to focus on her Environment portfolio.
There was uproar earlier this year after new funding rules around the purchasing of services were uploaded to the Ministry of Disabled People's Whaikaha website. Some community members felt "blind-sided" and said there had been no consultation.
At a press conference on Wednesday, Luxon said Lee's demotion is about recognising big changes in the media and ensuring there is a "good Cabinet Minister" in charge of the portfolio.
He said both portfolios had become significantly more "complex" since the Government took power six months ago.
He denied Lee being booted out of Cabinet was humiliating and said it was about the increase in "complexity".
The Prime Minister's full statement:
Paul Goldsmith will take on responsibility for the Media and Communications portfolio, while Louise Upston will pick up the Disability Issues portfolio, Prime Minister Christopher Luxon announced today.
"Our Government is relentlessly focused on getting New Zealand back on track. As issues change in prominence, I plan to adjust Ministerial responsibilities to make sure we are best set up to deliver for New Zealanders.
"It has become clear in recent months that there are significant challenges in the media sector. Similarly, we have discovered major financial issues with programmes run by the Ministry of Disabled People.
"I have come to the view it is important to have senior Cabinet Ministers considering these issues.
"There are significant synergies between the Arts, Culture and Heritage portfolio and Media and Communications - as such, I've asked Paul Goldsmith to take the lead on media issues for the Government.
"The challenges facing our media are being seen all over the world. While there are limited levers for Government here, I look forward to Paul progressing work to ensure regulatory settings are appropriate to enable the media to modernise and adapt to a changing media environment.
"The Ministry of Disabled People is a departmental agency within the Ministry of Social Development, so I have asked Louise Upston to take responsibility for the Disabilities Issues portfolio. This will free Penny Simmonds up to focus on the Environment portfolio and the major changes she is progressing to improve tertiary education.
"Given the changes, Melissa Lee will move outside of Cabinet. Climate Change and Revenue Minister Simon Watts will move into Cabinet.
"The Prime Minister has advised the Governor-General to give effect to the changes today."