A hand-held point of care monitoring system that includes a plurality of assay modules configured to receive different assay devices that perform assays on one or more samples. At least two of the assay modules or at least two of the assay devices have different identifiers that identify the assays. The system also includes an apparatus having a portable frame configured to interchangeably receive the plurality of assay modules in a same port; a means for decoding the different identifiers when received by the frame; and a means for reading assay results.