Inclusion Criteria:

• At least 18 years old or having attained the minimum age of independent consent, as defined by the local IRB, whichever is greater
• Confirmed HIV infection, documented by the results of tests performed on two separate specimens at any time prior to study entry
• Documentation of hepatitis C (HCV) antibody, hepatitis B surface antibody (HBsAb), and hepatitis B surface antigen (HBsAg) status (if HBsAb status is negative) within 12 months prior to study entry
• Between delivery and 28 days postpartum
• Antiretroviral (ARV) treatment naïve, defined as having received less than 14 days of one or more antiretroviral agents prior to therapy initiated during current pregnancy NOTE: History of receipt of ARV for perinatal mother-to-child transmission (PMTCT) during prior pregnancies and immediately postpartum is permitted.
• Receipt of at least 4 weeks of HAART without interruption prior to study entry, at least 2 weeks of which must have been received prior to delivery. HAART is defined as three or more agents from two or more classes of antiretroviral therapy (ART). Treatment interruption is defined as more than seven consecutive days of missed therapy.

NOTE: Women on a triple nucleoside regimen during pregnancy are eligible but will be switched to a study-provided HAART regimen if randomized to continue HAART (Arm A).

• CD4 cell count of 400 cells/mm3 or greater on a specimen obtained within 60 days prior to initiation of HAART for current pregnancy

NOTE: This result will be obtained from the participant's medical records, if available.

• CD4 cell count of 400 cells/mm3 or greater on HAART and on a specimen obtained within 45 days prior to study entry
• Certain laboratory values on a specimen obtained within 45 days prior to study entry. More information on this criterion can be found in the protocol.
• Estimated creatinine clearance greater than or equal to 60mL/min within 45 days prior to entry
• Intent to remain in current geographical area of residence for the duration of the study
• Willingness to attend visits required by the study

Exclusion Criteria:

• Previous participation in PROMISE study (P1077)
• Receipt of tuberculosis (TB) treatment within 30 days of study entry
• Clinical indication for HAART, defined as WHO Clinical Stage 3 or 4
• Serious illness requiring systemic treatment and/or hospitalization until participant either completes therapy or is clinically stable on therapy, in the opinion of the investigator, for at least 30 days prior to study entry
• Social or other circumstances which, in the opinion of the site investigator, would hinder long-term follow up
• Use of any prohibited medications within 14 days prior to study entry (refer to the study manual of procedures [MOP] for a list of prohibited medications)
• Current compulsory detention (involuntary incarceration) in a correctional facility, prison, or jail for legal reasons or compulsory detention in a medical facility for treatment of either a psychiatric or physical (e.g., infectious disease) illness
• Currently breast feeding or planning to breast feed
• History of documented structural or conduction heart defect (specialized assessments to rule out this condition are not required, and a heart murmur alone is not considered exclusionary)
• Known evidence of Hepatitis B virus (HBV) DNA levels greater than 2000 IU/mL (approximately 10,000 copies/mL) in the presence of elevated ALT (testing for this is not required for study screening or enrollment)