A three-time IBMA guitarist of the year, Grier has been lauded as highly influential and a master flatpicker by music publications and several of his colleagues.

[9] Grier's father Lamar was a banjo player in Bluegrass legend Bill Monroe's band for a number of years.

[9] During the 1980s, he performed with Country Gazette and Doug Dillard, and then began to record his own albums beginning with Freewheeling in 1988.

[11] Grier performs solo and as a member of the group Psychograss, founded by Darol Anger and Mike Marshall.

[12] In 2015, bluegrass supergroup Helen Highwater, consisting of Grier, Shad Cobb (fiddle), Missy Raines (bass), and Mike Compton (mandolin), released one self-titled EP.