The new stance would is designed to ensure at least two experienced players in each position are available for selection for the national team.
The rules will mean that if South African scrum-half Ruan Pienaar continues to play for Ulster, neither Leinster nor Munster would be able to sign a foreign scrum-half.
The changes will come into play at the start of the 2013/14 season, although the rules will not apply to Connacht who are currently implementing the recommendations of a structural review by the IRFU.
The reduction of foreign imports is just one of a number of new initiatives, with all having been agreed by the provinces and the IRFU who are keen to ensure greater game time for former academy players.
"The challenge for the IRFU in an increasingly competitive environment is to strike a long-term balance between success for the Ireland team, through exposing Irish players at the highest level of the professional club game in the Heineken Cup and RaboDirect PRO12 and the needs of the provincial teams in terms of the recruitment of quality overseas playing talent to complement Irish qualified players," read an IRFU statement.
"The following principles are designed to deliver at least two suitably experienced Irish players in all 15 field positions for national team selection:
"One non-Irish eligible (NIE) player only in each of the 15 field positions across the provinces of Leinster, Munster and Ulster e.g. one foreign player allowed across all three teams per position.
"For the 2013/14 season and onwards, for any given position involving a contracted NIE player, a province will not be permitted to renew that NIE player contract or bring in a new NIE player into that same position in its squad.
"All future provincial injury replacement players must be eligible for selection for Ireland.
"All future provincial non-Irish eligible player contracts will be position specific.
"The desired outcome of the changes to contract policies is that Irish-qualified players who have progressed through the provincial Academy systems will see greater opportunities for professional game-time experience, allowing both the IRFU and provinces to deliver the maximum amount of value for the €2.5million that is invested annually across the four provincial Academies."