The objective of the Phase III of this project is to validate and calibrate the MEPDG for the concrete pavement design in Oklahoma. Both jointed plain concrete pavement (JPCP) and continuously reinforced concrete pavement (JPCP) were considered. Seven LTPP segments and 50 PMS pavement segments, including 30 JPCPs and 20 CRCPs, were selected and used in the local validation/calibration analyses. The suitability of the national default design models in the MEPDG were assessed by comparing the measured field pavement performance recorded in the PMS and the predicted pavement performance by the MEPDG. It was found that the national default MEPDG under-predicted the transverse joint faulting for doweled JPCPs in Oklahoma. The faulting model has been calibrated based on the Oklahoma PMS data. The national default transverse cracking model seems to be adequate, but more data are needed to confirm this observation. There is also not enough information to evaluate the suitability of the CRCP punchout model due to the limited number of CRCPs in Oklahoma. Both the transverse cracking model and the punchout model need to be revisited when more pavement distress data become available. Finally, recommendations were made on using the MEPDG to design concrete pavements in Oklahoma.