A method (200) for operating an exhaust gas system (120) that includes a first catalytic converter (122) and at least one second catalytic converter (124), which are both arranged downstream from an internal combustion engine (110) The internal combustion engine (110) is controlled to generate a rich exhaust gas having a first rich gas portion, (220) a fill level of the second catalytic converter (124) is ascertained with respect to at least one lean gas component that is storable in the second catalytic converter and, if the ascertained fill level drops below (230) a minimum fill level, (240) the internal combustion engine (110) is controlled to generate a lean exhaust gas. The internal combustion engine (110) is then controlled to generate a rich exhaust gas having a second rich gas portion, and subsequently controlled (210) to generate the rich exhaust gas having the first rich gas portion.