CE-500 pilot reported departing the taxiway after losing directional control while taxiing. Aircraft was towed to the hangar where inspection revealed the left rudder pedal had caught on the carpet that was installed adjacent to the rudder pedal.

Narrative

While taxiing at ZZZ on Day 0 morning en route to Runway ZZ via Taxiway 1; I performed a standard brake check and confirmed normal function. The taxi was smooth; and we proceeded after clearance. However; during a turn to enter the runway; the aircraft unexpectedly lost directional control and began veering left. I attempted correction with the top right brake and added right engine power; but the aircraft exited the paved taxiway and entered the grass.I followed the checklist; shut down the aircraft; and deplaned by training. Upon inspection; we found the left main gear had left the taxiway surface but caused no damage to airport infrastructure; signage; or lighting.Contributing factors: Post-incident inspection revealed the cause: the left rudder pedal had become jammed due to interference from the lining or carpet on the left cabin wall. This caused the rudder to stick; making directional control impossible during the taxi turn.Corrective actions taken: The aircraft was towed to the hangar. After cleaning and adjusting the cabin interior; we tested the aircraft from both the left and right seats. No issues reoccurred; and we completed the subsequent flight to ZZZ1 without incident.