An electronic on-body injector for use with a patient to deliver a fluid through an injection device having an injection port in fluid communication with a delivery tube, the injection port lying on an injection axis, the electronic on-body injector comprising: a fluid reservoir operable to hold the fluid; a MEMS pump in fluid communication with the fluid reservoir; a bolus injection needle in fluid communication with the MEMS pump, the bolus injection needle having a bolus injection needle tip aligned with the injection port, the bolus injection needle being slideably biased away from the injection port to define a gap between the bolus injection needle tip and the injection port; and a bolus needle button operably connected to the bolus injection needle to slide the bolus injection needle along the injection axis; wherein the bolus needle button is operable to advance the bolus injection needle tip to close the gap and advance the bolus injection needle tip into the injection port to form a bolus injection flow path from the fluid reservoir, through the MEMS pump, through the bolus injection needle, through the delivery tube, and into the patient; wherein the bolus needle button is further operable to activate the MEMS pump to deliver a predetermined bolus volume to the patient through the bolus injection flow path in response to a bolus pump drive signal, and wherein the MEMS pump is further in fluid communication with the delivery tube to form a basal injection flow path from the fluid reservoir, through the MEMS pump, through the delivery tube, and into the patient, the MEMS pump being further operable to deliver a basal injection to the patient through the basal injection flow path in response to a basal pump drive signal. a fluid reservoir operable to hold the fluid; a MEMS pump in fluid communication with the fluid reservoir; a bolus injection needle in fluid communication with the MEMS pump, the bolus injection needle having a bolus injection needle tip aligned with the injection port, the bolus injection needle being slideably biased away from the injection port to define a gap between the bolus injection needle tip and the injection port; and a bolus needle button operably connected to the bolus injection needle to slide the bolus injection needle along the injection axis; wherein the bolus needle button is operable to advance the bolus injection needle tip to close the gap and advance the bolus injection needle tip into the injection port to form a bolus injection flow path from the fluid reservoir, through the MEMS pump, through the bolus injection needle, through the delivery tube, and into the patient; wherein the bolus needle button is further operable to activate the MEMS pump to deliver a predetermined bolus volume to the patient through the bolus injection flow path in response to a bolus pump drive signal, and wherein the MEMS pump is further in fluid communication with the delivery tube to form a basal injection flow path from the fluid reservoir, through the MEMS pump, through the delivery tube, and into the patient, the MEMS pump being further operable to deliver a basal injection to the patient through the basal injection flow path in response to a basal pump drive signal.