Micellar casein is a relatively new dairy protein concentrate that can be used in process cheese products (PCP). PCP is a dairy food prepared by blending and heating various dairy and non-dairy ingredients to produce a pasteurized product with an extended shelf life. The objective of this study was to utilize highly concentrated micellar casein (HC-MC) as an ingredient in PCP and examine the effect of storage (0, 30, and 60 d at 4°C) of HC-MC on functionality of PCP. PCP formulations were prepared by mixing all ingredients (aged Cheddar cheese, HC-MC, water, unsalted butter, deproteinized whey, sodium phosphate dibasic, salt, and sodium citrate) in a kitchenaid at room temperature for 30–40 min to produce a homogeneous paste. A 25g sample of the mixture was weighed in a canister (5 replicates) and tempered at 38°C for 15–20 min and then cooked in the rapid visco analyzer (RVA) for 4 min at 90°C. The stirring speed was 1000 rpm during the first 2 min of the test and was then reduced to 160 rpm during the final 2 min. Once the PC was cooked, it was poured in molds and stored at 4°C for further analysis. This experiment was repeated 3 times using 3 different batches of HC-MC at each time point of storage (0, 30, and 60 d). The functionality of the PCP was measured by determining the cooked viscosity, texture profile analysis (TPA) hardness, and dynamic stress rheometry (DSR) melt temperature. The moisture content and pH of the PCP was not affected (P > 0.05) by storage of the HC-MC and ranged from 47.1 to 48.1% and 5.70–5.71 respectively. The cooked viscosity of the PCP was not affected (P > 0.05) by storage of the HC-MC and ranged from 755 to 769cP. However, there was a small but significant (P < 0.05) decrease in TPA hardness (135 to 105g) and DSR melt temperature (58.4 to 56.4°C) with HC-MC storage. This study demonstrates that HC-MC can be utilized in PCP formulations and small but significant changes in functionality were observed when the HC-MC was stored at 4°C for 60 d.