New measurements in the (A) over tilde (1)A " - (X) over tilde (1)A' band system of monobromomethylene (HCBr) at near-infrared wavelengths are reported. Rotationally resolved spectra of HCBr and DCBr for both naturally occurring Br isotopes are analyzed and provide accurate energies for the low-lying bending vibrational levels in both the (A) over tilde and (X) over tilde states. The experimental results are compared to extensive ab initio calculations of these two states and the low-lying (a) over tilde (3)A " state. The ab initio T-00 value for the (A) over tilde-(X) over tilde system is calculated within 500 cm(-1) of the experimental results. For the triplet state, T-00 (<()over tilde>-(X) over tilde) was calculated to be 1833 cm(-1). The measurements of the bending intervals in the (X) over tilde (1)A' state suggest that this is about 250 cm(-1) too low. With this shift and inclusion of spin-orbit coupling between the (a) over tilde and (X) over tilde states, the calculated bending vibrational levels in the (X) over tilde state reproduce the observations, and the calculations make testable predictions of the position of the triplet and other singlet state vibronic levels. Combining the experimental and computational results, we estimate the triplet, T-00(<()over tilde>-(X) over tilde), excitation energy to be 2028 cm(-1).