Outpatient parenteral antibiotic therapy, OPAT, has become a standard of care in the United States as well as some other countries especially in Europe. The potential benefits of OPAT include avoidance of inpatient admission or shortened inpatient stay, both of which reduce patient exposure to nosocomial pathogens while reducing costs in enhancing patient comfort by allowing them to reside outside the hospital. Safe and effective OPAT requires oversight by the Antimicrobial Stewardship Program given its complexities. At a minimum, all patients who are potential OPAT candidates should undergo infectious disease consultation and, or stewardship program review, and should be carefully followed by them for the duration of OPAT. While a number of criteria for appropriateness of OPAT can be used, the basic issue is this: if the only reason the patient requires inpatient status is antimicrobial therapy, they probably should not be an inpatient, assuming of course, that there is a safe environment for outpatient therapy. More precisely, the following are among the questions that must be addressed in deciding whether a patient is suitable for OPAT. Does the patient, in fact, require antibiotic therapy? Is the patient's status sufficiently stable to allow discharge to an outpatient setting? Does the patient require continued administration of an antibiotic by the intravenous route or can the treatment be completed with orally-administered antibiotics? Is there an antibiotic effect in the treatment of the infection that is suitable for instance, has adequate stability for outpatient administration? Is the patient and if relevant, the patient's caregiver, capable of dealing with the demands of OPAT? This might include understanding the elements of administration in the home, availability of transportation to an infusion center and the like. Finally, is OPAT financially feasible for the patient? For the patient who is deemed by consultation to be an OPAT candidate, the consultant and our stewardship team should determine the following: What is the appropriate vascular access device? In general, if therapy is to be administered in the outpatient setting for seven days or fewer, a peripheral IV may be used, and it only requires changing rather when clinically indicated. Alternatively, a midline catheter can be used and perhaps most popularly a PICC line is used, and this is recommended if greater than 15 days of therapy is to be administered or the antibiotic is likely to cause phlebitis. It's also recommended that this be avoided in patients with advanced chronic kidney disease to preserve vessels for subsequent AV fistula formation. A third alternative is a cuffed central catheter or a tunneled small-bore catheter or an implanted port. The appropriate antibiotic or the antibiotics and appropriate dose and infusion duration taking into account, pharmacokinetics and pharmacodynamics must be determined. There must be avoidance of drug-drug interactions. Finally, there must be a plan for the duration of therapy. OPAT may be avoided in some patients who are not candidates for oral antibiotic administration by giving agents with extraordinarily long serum half-life such as dalbavancin or oritavancin at the time of discharge. In the United States, these drugs as of April of 2017, have received FDA approval only for the treatment of adults with acute bacterial skin and skin structure infections due to susceptible organisms such as Streptococcus pyogenes and Staphylococcus aureus, including MRSA. However, their acquisition costs are quite high and this presents a dilemma to hospitals' inpatient pharmacies because they shift the cost of antibiotics for the drug from the outpatient to the inpatient pharmacy. Monitoring of the patient receiving OPAT requires regular face-to-face visits, as well as so-called virtual visits and includes evaluation of the response to therapy, evaluating opportunities to convert from parenteral to oral antibiotic administration, safety evaluation including recognition of drug toxicity, drug-drug interactions, evaluation for complications of vascular access devices and the like, recognition of secondary infections including that those due to Clostridium difficile, and the decision to discontinue therapy when maximum benefit has been reached. Laboratory evaluation must be performed at least weekly with individual tests determined by the antibiotic or antibiotics being administered, and testing must be carefully tracked by the Stewardship Program. The aim of the laboratory testings include monitoring of response to therapy, the recognition of toxicity as, for instance, eosinophilia, germination of cytopenias, kidney injury or myositis and therapeutic drug monitoring when indicated. Often overlooked but necessary is continual monitoring of OPAT safety and efficacy for the purposes of quality improvement. The program should record and continually evaluate outcomes including resolution of infection, adverse events, as well as the number of and reasons for readmission. These should be recorded and continually evaluated.