An anchoring member for a polyaxial bone anchoring device includes a bone anchoring section having a first end, a second end, and a bone engagement structure, a head having an outer surface portion that defines a segment of a sphere, wherein a central axis extends through the head and the first and second ends of the bone anchoring section, and a neck extending between the first end of the bone anchoring section and the head. The neck has a first portion and a second portion between the first portion and the bone anchoring section. In at least a first cross-sectional plane including the central axis, the first portion of the neck is concave with a first curvature, and the second portion of the neck is concave with a second curvature that is less curved than the first curvature.
