A convertible bearing cage is provided including a first cage part having a first rim with a plurality of first projections extending axially therefrom that form open, snap-in pockets for receiving bearing balls. Connection holes are located in the projections. A second cage part having a second rim with a plurality of second projections extending axially therefrom that form partial pockets is also provided. The plurality of second projections are aligned with the first projections. A ring guide extends circumferentially around the second rim. The second cage part is connectable to the first cage part with the second plurality of projections contacting the first priority of projections using connection elements that engage in or through the connection holes to form closed pockets. The first cage part is used alone as an open pocket, ball guided cage, or connected to the second cage part as a closed pocket, ring guided cage.