Described herein are Fc variants and methods for the efficient production of antibodies and other multimeric protein complexes (collectively referred to herein as heteromultimeric proteins). Heteromultimeric proteins may be capable of specifically binding to more than one target. The targets may be, for example, different epitopes on a single molecule or located on different molecules. The methods combine efficient, high gene expression level, appropriate assembly, and ease of purification for the heteromultimeric proteins. The invention also provides methods of using these heteromultimeric proteins, and compositions, kits and articles of manufacture comprising these antibodies.