To test the effectiveness of Prepmate, a novel multi-modal, technology-based intervention for pre-exposure prophylaxis (PrEP) adherence support among young men who have sex with men (MSM).

Inclusion Criteria:

• HIV-uninfected as determined by a negative/non-reactive laboratory test within 7 days of Enrollment (as defined in the study-specific procedures (SSP) Manual).

• Interested in initiating PrEP

• Eligible to initiate PrEP

  • Creatinine clearance > 60 ml/min as estimated by the Cockcroft-Gault equation within 6 weeks of enrollment
  • Hepatitis B surface antigen (HBsAg) negative within 6 weeks Enrollment
  • No other medical contraindications to PrEP

• Age 18 years - 29 years

• Willing and able to provide written informed consent

• Report having had anal sex with a man in the previous 6 months

• Meet any of the following risk criteria for the prior 6 months:

  • Any condomless anal sex
  • Three or more anal sex partners
  • Self-reported new STI
  • Known HIV-infected sex partner

• Have regular access to a computer and/or a smart phone to access the internet and/or apps

• Have the ability to send and receive text messages

• Able to read and speak in English

Exclusion Criteria:

• PrEP use within the past year (PrEP naïve participants will be prioritized).
• Any reactive or positive HIV test at Screening, even if subsequent testing indicates that the person is HIV-uninfected
• Prior or current participation in the active arm of an HIV vaccine trial
• At Enrollment, has any other condition that, based on the opinion of the investigator or designee, would preclude provision of informed consent, make participation in the project unsafe, complicate interpretation of outcome data, or otherwise interfere with achieving the project objectives.
• Signs or symptoms of acute HIV infection (as described in the SSP Manual)
• History of pathological bone fracture not related to trauma.