Duties The full performance level of this vacancy is GS 08. The actual grade at which an applicant may be selected for this vacancy is in the range of GS 04 to GS 08. At all levels MRTs (Coder) may be assigned to a single facility or region, such as a consolidated coding unit. They select and assign codes from current versions of ICD CM, PCS, CPT, and HCPCS classification