Motivated by the observed shortfall of baryons in the local universe, we investigate the ability of high-resolution cosmic microwave background (CMB) experiments to detect hot gas in the outer regions of nearby group halos. We construct hot gas models with the gas in hydrostatic equilibrium with the dark matter and described by a polytropic equation of state. We also consider models that add entropy to the gas in line with constraints from X-ray observations. We calculate the thermal Sunyaev-Zel'dovich (tSZ) signal in these halos and compare it to the anticipated sensitivities of forthcoming tSZ survey experiments such as Antenna Cosmology Telescope, PLANCK, and South Pole Telescope. Using a multifrequency Wiener filter we derive tSZ detectability limits as a function of halo mass and redshift in the presence of galactic and extragalactic foregrounds and the CMB. We find that group-sized halos with virial masses below 1014 M sun can be detected at z lsim 0.05 with the threshold mass dropping to (3-4) × 1013 M sun at z lsim 0.01. The tSZ distortion of nearby group-sized halos can thus be mapped out to the virial radius by these CMB experiments, beyond the sensitivity limits of X-ray observations. These measurements will provide a unique probe of hot gas in the outer regions of group halos, shedding insight into the local census of baryons and the injection of entropy into the intragroup medium from nongravitational feedback.