The shock tube technique was used to study the high temperature thermal decomposition of dimethyl carbonate, CH3OC(O)OCH3 (DMC). The formation of H-atoms was measured behind reflected shock waves by using atomic resonance absorption spectrometry (ARAS). The experiments span a T-range of 1053-1157 K at pressures similar to 0.5 atm. The H-atom profiles were simulated using a detailed chemical kinetic mechanism for DMC thermal decomposition. Simulations indicate that the formation of H-atoms is sensitive to the rate constants for the energetically lowest-lying bond fission channel, CH3OC(O)OCH3 -> CH3 + CH3OC(O)O [A], where H-atoms form instantaneously at high temperatures from the sequence of radical beta-scissions, CH3OC(O)O -> CH3O + CO2 -> H + CH2O + CO2. A master equation analysis was performed using CCSD(T)/cc-pv infinity z//M06-2X/cc-pvtz energetics and molecular properties for all thermal decomposition processes in DMC. The theoretical predictions were found to be in good agreement with the present experimentally derived rate constants for the bond fission channel (A). The theoretically derived rate constants for this important bond-fission process in DMC can be represented by a modified Arrhenius expression at 0.5 atm over the T-range 1000-2000 K as, k(A)(T) = 6.85 X 10(98)T(-24.239) exp(-65250 K/T) s(-1). The H-atom temporal profiles at long times show only minor sensitivity to the abstraction reaction, H + CH3OC(O)OCH3 -> H-2 + CH3OC(O)OCH2 [B]. However, H + DMC is an important fuel destruction reaction at high temperatures. Consequently, measurements of D-atom profiles using D-ARAS allowed unambiguous rate constant measurements for the deuterated analog of reaction B, D + CH3OC(O)OCH3 -> HD + CH3OC(O)OCH2 [C]. Reaction C is a surrogate for H + DMC since the theoretically predicted kinetic isotope effect at high temperatures (1000 - 2000K) is close to unity, k(C) approximate to 1.2 k(B). TST calculations employing CCSD(T)/cc-pv infinity z//M06-2X/cc-pvtz energetics and molecular properties for reactions B and C are in good agreement with the experimental rate constants. The theoretical rate constants for these bimolecular processes can be represented by modified Arrhenius expressions over the T-range 500-2000 K as, k(B)(T) = 1.45 X 10(-19T2.827) exp(-3398 K/T) cm(3) molecule(-1) s(-1) and k(C)(T) = 2.94 X 10(-19T2.729) exp(-3215 K/T) cm(3) molecule(-1) s(-1).