In this work the charm and bottom quark masses are determined from QCD moment sum rules for the charmonium and upsilon systems. To illustrate the special character of these sum rules when applied to Coulomb systems, we first set up and study the behavior of the sum rules in quantum mechanics. In our analysis, we include both the results from nonrelativistic QCD and perturbation theory at next-next-to-leading order. The moments are evaluated at different values of ${q}^{2}$ which correspond to different relative influences among the theoretical contributions. In the numerical analysis, we obtain the masses by choosing central values for all input parameters. The error is estimated from a variation of these parameters. First, the analysis is performed in the pole mass scheme. Second, we employ the potential-subtracted mass in intermediate steps of the calculation to then infer the quark masses in the $\overline{\mathrm{MS}}$ scheme. Our final results for the pole and $\overline{\mathrm{MS}}$ masses are ${M}_{c}=1.75\ifmmode\pm\else\textpm\fi{}0.15\mathrm{GeV},{m}_{c}{(m}_{c})=1.19\ifmmode\pm\else\textpm\fi{}0.11\mathrm{GeV},{M}_{b}=4.98\ifmmode\pm\else\textpm\fi{}0.125\mathrm{GeV},$ and ${m}_{b}{(m}_{b})=4.24\ifmmode\pm\else\textpm\fi{}0.10\mathrm{GeV}.$