The versatile Ireland international who joined Munster on a two-year deal last summer has now committed to the province for a further two years.
In starting 18 of his 20 appearances to-date, the 27-year-old lock has also scored 2 tries.
Recognised for his impressive work-rate at the breakdown, he deservedly won Man of the Match awards at home and away against Exeter Chiefs in the Champions Cup, and against Leinster, Ospreys and Connacht in the Guinness PRO14.
The turnover king topped the charts in the Champions Cup with 15 turnovers, and following committed performances in red he was nominated for Munster Rugby Player of the Year by his fellow team-mates in April.
On the international stage, Beirne has five Ireland caps, and made his Six Nations debut starting against Wales in March.
Further positive news for the province sees Academy scrum-half Craig Casey advance to a development contract at the start of next season, moving to a full contract at the beginning of the 2020-21 season.
Coming to the end of his second year of the academy, the talented number 9 played a leading role in the Ireland U20s Grand Slam winning campaign. Named squad vice-captain, he started against France, Italy and England, and scored two tries.
Most recently, the 20-year-old was named Munster Rugby Academy Player of the Year before going on to make his Guinness PRO14 debut as a replacement against Connacht in Thomond Park.
Playing his club rugby with Shannon RFC, the promising young player continues to follow in the footsteps of his uncle, former Munster back Mossy Lawler, while his father Gerry is a Rugby Development Officer with the province.