HIV testing is the cornerstone of HIV prevention. CDC recommends HIV testing at least annually for persons at risk of HIV infection. Previous modeling studies have suggested that HIV testing more frequently would be unlikely to be cost-effective at the population level. These models, however, did not incorporate the benefits of linkage to PrEP (soon after initiation of indicating risks) and immediate HIV treatment (for diagnosed infected persons) that would improve with increased testing. Our prior PrEP model also found that nearly half of at-risk MSM were missed by standard HIV testing frequencies that lead to PrEP evaluation. We propose to build on the existing model platform to investigate the HIV prevention benefits of a three-pronged strategy to reduce HIV incidence through: 1) more frequent diagnostic HIV testing; 2) immediate HIV treatment for persons with diagnosed acute and early HIV infection; and 3) PrEP for those who test negative but are at high risk. The project will evaluate the relative benefits of each of these components independently and in combination to identify the optimal mix of these strategies for both public health impact (number of infections averted) and efficiency (cost-effectiveness).