Despite high efficacy and 11 years of availability, access to HIV preexposure prophylaxis (PrEP) remains limited; only 30% of the 1.2 million people in the US likely to benefit from PrEP were prescribed it in 2021, with stark racial and ethnic inequities in its use. 1 One major barrier to using PrEP is lack of access to health care. However, even for people engaged in the health care system, access can be constrained by policies that determine when, where, how, to whom, and at what cost PrEP is provided. When those policies are driven by private sector interests, they represent commercial determinants of health-the systems, practices, and pathways through which commercial actors impact health and equity. 2 McManus et al 3 assessed commercial determinants of PrEP access within the health care sector from 2018 through 2020, including insurance coverage, prior authorization requirements, and specialty tiering of PrEP medications in qualified health plans (ie, those certified by the Patient Protection and Affordable Care Act [ACA] Health Insurance Marketplace). The authors 3 investigated these policies for the 2 available formulations of oral PrEP. Emtricitabine/tenofovir disoproxil fumarate was approved for use as daily oral PrEP in 2012 in all populations; in 2019, emtricitabine/ tenofovir alafenamide was approved for use as daily oral PrEP among men and transgender women who have sex with men, the only populations in which its efficacy was studied. The 2 medications were priced at over $20 000 annually per person during the study period, 3 making coverage essential for those accessing PrEP through insurance plans.McManus et al 3 found that coverage for PrEP medications was high among qualified health plans, which is consistent with reports suggesting that most people can access PrEP at low or no cost. 4 However, the study's results are also consistent with prior evidence that it is often not the out-of-pocket costs but the complexity of obtaining financial coverage-through health plans for insured people or assistance programs for uninsured people-that deters people from using PrEP. 5 The authors 3 found that 15% to 20% of plans placed PrEP medications on specialty tiers and that prior authorization requirements were common, particularly for emtricitabine/tenofovir disoproxil fumarate, the older medication. Plans that required prior authorization exclusively for emtricitabine/ tenofovir disoproxil fumarate were more prevalent in jurisdictions designated as high-priority by the US Ending the HIV Epidemic Initiative and in the South, the region with the highest unmet need for PrEP. 3 Notably, exclusive prior authorization for emtricitabine/tenofovir disoproxil fumarate increased substantially in 2020, 3 just before it went generic.The McManus et al 3 study demonstrates that insurance policies could impede access to PrEP for the millions of people who are insured by qualified health plans. Although coverage of at least 1 PrEP option was high, it was not universal. Specialty tiering, which can require higher out-of...