The neutron-deficient nucleus $^{199}\mathrm{At}$ has been studied through $\ensuremath{\gamma}$-ray and electron spectroscopy, using the recoil-decay tagging technique. Two experiments were conducted, using a gas-filled recoil separator with a focal-plane spectrometer alone and together with a germanium-detector array at the target position. The resulting level scheme for $^{199}\mathrm{At}$ includes a new isomer with a half-life of 0.80(5) $\ensuremath{\mu}$s and a spin and parity of ($29/{2}^{+}$). The $13/{2}^{+}$ isomer, which de-excites via an $M2$ transition to the $9/{2}^{\ensuremath{-}}$ ground state, was measured to have a half-life of 70(20) ns. Our earlier version of the level scheme for $^{197}\mathrm{At}$ has been updated as well.