Method and system for determining real time analyte concentration including an analyte sensor having a portion in fluid contact with an interstitial fluid under a skin layer, an on-body electronics including a housing coupled to the analyte sensor and configured for positioning on the skin layer, the on-body electronics housing including a plurality of electrical contacts, on the housing; and a data analysis unit having a data analysis unit housing and a plurality of probes, on the housing. Each of the probes configured to electrically couple to a respective electrical contact when the data analysis unit is positioned in physical contact with the on-body electronics. The one or more signals on the probes correspond to one or more of a substantially real time monitored analyte concentration level (MACL), MACL over a predetermined time period, or a rate of change of the MACL, or combinations thereof, are provided.