Andy Farrell heads the list of Ireland's assistant coaches who have extended their contracts until 2020.
Greg Feek will shortly join Japanese club side Ricoh -- but will also maintain his scrum coach role with Ireland until after the 2019 World Cup.
Defence coach Farrell, forwards specialist Simon Easterby and skills coordinator Richie Murphy, however, have all signed contract extensions to run until 2020.
Boss Joe Schmidt's contract expires after the 2019 World Cup, and former England coach Farrell's new deal could leave him well positioned to take the helm in time.
Ireland's Kiwi head coach Schmidt could well seek a move back to New Zealand after the World Cup, with Farrell in the frame to take charge.
"Ireland forwards coach Simon Easterby, defence coach Andy Farrell, scrum coach Greg Feek and skills coach Richie Murphy have signed contract extensions that will see them continue with the national team through the Rugby World Cup in Japan," read an Irish Rugby Football Union (IRFU) statement.
"Simon Easterby joined the Ireland coaching ticket in 2015 having previously held the position of head coach at Llanelli Scarlets. Easterby has extended his IRFU contract to June 2020.
"Ireland defence coach Andy Farrell has extended his contract through to June 2020 while Richie Murphy who joined the national coaching group in 2014 from Leinster has also extended his role as national skills and kicking coach to June 2020."
Former All Blacks prop Feek has been involved with Ireland since 2011 but assumed a full-time role in 2014.
The 42-year-old will now seek to juggle his forthcoming role in Japan with his Ireland commitments.
"Greg Feek joined the national coaching group on a full-time basis in 2014 having previously worked with Leinster and with the national team on a consultancy basis," read the IRFU statement.
"Due to a change in personal circumstances Feek will take up a position with Japanese club side Ricoh in the coming weeks but will continue in his role with the Ireland national team through to the completion of the Rugby World Cup in Japan."
The current coaching crop have driven Ireland into second place in the world rankings, with Schmidt's men claiming the nation's third Grand Slam in the 2018 Six Nations.
"We have a world class coaching group that has driven and sustained high levels of performance on the international stage," said IRFU performance director David Nucifora.
"They also support the work of the provinces with their technical expertise and play an important role in the development of young players on the pathway to international honours."