Warrant Officer Class 1 (WO1) Michael Grant joined the Jamaica Defence Force in December 1992. During his tenure at the JDF, he completed a number of courses - PNCO Cadre in 1994, JNCO Cadre 1996, Military Police Investigation Course 1996, SNCO Cadre 1997, Sergeant Management Course (USA) 2004, Special Operation Course 2005, Range Management Course 2011, Service Fund Course 2011, Warrant Officer Course 2012, All Arm Drill Course 2014, Systematic Search Procedure Course 2015, Camp Sergeant Major course 2018 (Canada) and a Peer Support Counselling Course at the University of Technology in 2018.

In 1994, WO1 Grant was promoted to Lance Corporal and was deployed to Haiti for Operation Uphold Democracy. He continued rising through the ranks until his current appointment as Warrant Officer Class 1 in April 2021.

Since joining the JDF, WO1 Grant served in The First Battalion the Jamaica Regiment (1 JR), Support and Services Battalion 4 JR and the Health Services Corps (HSC).

WO1 Grant has held several military appointments including Squad Corporal, Platoon Sergeant, Chief Instructor for Military Training Wing and Search Advisor for the Caribbean Search Centre, Syndicate. He also served as the Company Sergeant Major for HQ 4JR and Sp Coy (Cbt Sp Bn), Drill Sergeant 4 JR, and Regimental Sergeant Major 4 JR and HSC.

He has been awarded the Medal of Honour General Service, Honour for Long Service and Good Conduct, First Bar to the Medal of Honour for Long Service and Good Conduct, the CDS Commendation Medal, United Nations Medal, Queen Jubilee Medal, and the Queen Platinum Medal.