Tim was born and raised in Kingsport, Tennessee. His mother's Browder side of the family was musical, and his twin sisters play piano and sing. After starting out on drums, Tim discovered bluegrass in the mid-1970s as a freshman at Ketron High School, becoming a banjo player. He switched to guitar in the late 70s and became a member of several groups, including Mountain Memories and The Boys in the Band. In the late 1980s, Tim formed Dusty Miller with Adam Steffey and Adam's wife at the time, Tammy Rogers (later a founding member of the Steeldrivers), Brian Fesler and Barry Bales. Alison Krauss hired Tim, Adam and Barry in 1990 and Union Station proceeded to record a Grammy-winning CD, Every Time You Say Goodbye (Rounder, 1992) and became one of the most influential bands in modern bluegrass history. After leaving the band in 1992 to spend more time with his family, including his infant son Daniel, Tim worked odd jobs and taught at different colleges and universities until he formed Blue Highway in 1994 with Wayne Taylor, Shawn Lane, Rob Ickes and Jason Burleson. The band released its 10th recorded project, The Game in January 2014, which went on to spend six months at the top of the Bluegrass Unlimited National Radio Survey. Their 20 years together with the same members is a record in bluegrass history; the band is one of the most decorated and influential in bluegrass history as well, having been nominated for 3 Grammys, winning a Dove Award, and nearly 30 IBMA Awards. In March 2016, Blue Highway was named the most popular bluegrass artist in history in an online poll by Bluegrass Today. In December 2016, their CD Original Traditional was nominated for a Grammy Award in the "Best Bluegrass Album" category.
Tim is a prolific songwriter, with over 225 songs recorded. He was named IBMA's Songwriter of the Year in 2014 and 2017. In addition, he is a sought-after studio musician, having recorded with over 75 artists in addition to Blue Highway, including Willie Nelson, Kenny Chesney, Jorma Kaukonen, Jesse McReynolds, Benny Sims, Marty Raybon, Joe Isaacs, Ronnie Bowman, Charles Sawtelle, Tony Trischka, Larry Sparks, Jim Mills and others. Tim was named SPBGMA Guitar Performer of the Year in 2001 and 2015. He has produced many award-winning records for various artists, including Kenny Chesney, The Infamous Stringdusters (IBMA 2007 co-album of the Year) , and Knee Deep in Bluegrass, the Acutab Sessions (IBMA 2001 Instrumental Recorded Performance of the Year). Tim performed many times with Hazel Dickens, including the Lincoln Center in New York (2006), Sundance Film Festival, Park City, UT (2005), Hardly Strictly Bluegrass, San Francisco, CA (2010), Wintergrass, Tacoma WA (2003). He has taught at every major bluegrass-oriented camp, including Rockygrass Academy, Camp Bluegrass (South Plains College, TX), Augusta Heritage, Wintergrass Academy, Sore Fingers (UK), Bluegrass at the Beach, Nashcamp, Kaufman's Flatpicking Camp, California Bluegrass Association Camp at Grass Valley, St. Louis Flatpick, Resosummit, Summergrass Academy, Grand Targhee, Bluegrass Masters Weekend, and Nashville Flatpick and Songwriting Camp.
Tim worked on a PhD in History at Miami University in the mid 1980s. He has taught American History, Western Civ, Appalachian Studies, Mass Communications and Popular Culture, Personal instruction in guitar and banjo, and Bluegrass Traditions at several colleges and Universities, including Miami, East Tennessee State, and Appalachian State University. He and Caroline Wright co-authored Still Inside: The Tony Rice Story, the critically-acclaimed authorized biography of bluegrass Hall of Fame member and living legend Tony Rice in 2010. Tim gave the keynote address at the 1994 IBMA World of Bluegrass in Owensboro, KY and has been on the IBMA Board of Directors two different times, serving as Vice Chair from 1995 to 1998. He is a Board member of the Foundation for Bluegrass Music and serves on several committees for IBMA. On May 8, 2015, Tim was named a Distinguished Alumnus in the Arts by the East Tennessee State University National Alumni Society.
Tim released his first solo record, Endless Line in 2004 on FGM Records to critical acclaim. It was nominated for IBMA’s Instrumental Recording of the Year in 2005. His second, Just to Hear the Whistle Blow, was released in July 2014, while his third, Acoustic Guitar, was released in September 2017.