We investigated limiting factors of carrier lifetimes and their enhancement by post-growth processes in lightly-doped p -type 4H-SiC epitaxial layers ( N A  ∼ 2 × 10 14 cm −3 ). We focused on bulk recombination, surface recombination, and interface recombination at the epilayer/substrate, respectively. The carrier lifetime of 2.8  μ s in an as-grown epilayer was improved to 10  μ s by the combination of V C -elimination processes and hydrogen annealing. By employing surface passivation with deposited SiO 2 followed by POCl 3 annealing, a long carrier lifetime of 16  μ s was obtained in an oxidized epilayer. By investigating carrier lifetimes in a self-standing p -type epilayer, it was revealed that the interface recombination at the epilayer/substrate was smaller than the surface recombination on a bare surface. We found that the V C -elimination process, hydrogen annealing, and surface passivation are all important for improving carrier lifetimes in lightly-doped p -type epilayers.