The goal of this paper is to showcase a modelling exercise, conducted for the Republic of Macedonia, a non-Annex I country under UNFCCC and a candidate for EU membership, by making use of MARKAL energy system model. Baseline Scenario and three groups of mitigation scenarios have been developed until 2050, reflecting different types of targets with different levels of ambition regarding CO2 emissions reduction: (1) EU scenarios end-year targets compared to 1990 level; (2) QELRC (Quantified Emission Limitation and Reduction Commitment) scenarios a range of targets over the period 2021-28 and for each subsequent 8-year period, and (3) Baseline deviation scenarios deviation compared to baseline emission level. The comparative assessment of mitigation scenarios, based on the cumulative emissions, cumulative total system costs and incremental specific reduction cost, has generated a basis for setting the national mitigation contributions and formulating the most appropriate national mitigation action plan. (C) 2015 Elsevier Ltd. All rights reserved.