This study is looking at the safety and effectiveness of treating Patients diagnosed with a low-risk Pulmonary Embolism (PE) in an outpatient setting instead of the standard, in-patient hospitalization. Patients have several medical tests done during their Emergency Department visit. Based on those tests, those who are determined to have a low-risk PE are eligible to participate in the study. Those choosing to participate are discharged after 12 hours of medical observation. Patients who choose to participate are followed up by telephone approximately 90 days later.

Inclusion Criteria:

1. Pulmonary Embolism, diagnosed by CTA or high probability VQ Scan
2. Total Pulmonary Embolism Severity Index (PESI) score <86

Exclusion Criteria:

1. Massive Pulmonary Embolism: Hypotension with signs of right heart strain on CTA or Echocardiogram
2. Sustained Systolic Blood Pressure (SBP) <95 mmHg during Emergency Department or observation stay.
3. Age <18
4. Pregnant
5. Renal insufficiency (Creatinine Clearance <30)
6. Hepatic Dysfunction (AST/ALT/ALP > 3 times upper limit of normal)
7. Unreliable social situation or inability to follow up
8. Contraindication to enoxaparin, warfarin and rivaroxaban
9. Atrial or ventricular dysrhythmia(s)

The subject population is drawn from patients arriving in the Emergency Department who are then diagnosed with a lower risk pulmonary embolism (PESI score <86).