Background Black cisgender women are disproportionately affected by HIV across the United States (US). Moreover, emerging adults continue to be significantly affected compared to women in older age groups. Yet in 2024, Black cisgender women and emerging adult women comprise a small fraction of HIV pre-exposure prophylaxis (PrEP) users in the US. This study examined PrEP modality, service delivery, and marketing and communication preferences by age among Black cisgender women in Baltimore, Maryland. Methods Between October 2021 and April 2023, twelve Black cisgender PrEP-inexperienced emerging (18 to 29 years) and fourteen older (30 to 44 years) adult women were purposively recruited to participate in an in-depth interview. Interview topics included PrEP modality, service delivery, and marketing and communication preferences among the two currently approved modalities (oral and injectable) and the two modalities under investigation (ring and implant). Interviews were audio-recorded, transcribed verbatim, and analyzed using a combination of a deductive and inductive approach. Six follow-up member-checking interviews were also conducted. Results Emerging adult women preferred oral PrEP, but older adult women preferred long-acting injectable (LAI) forms of PrEP. Oral PrEP was preferred because it was considered the most common modality for other medications, whereas LAI was preferred because it didn't necessitate no daily administration. Emerging Black adult women reported challenges with adhering to the routine PrEP three-month follow-up period, such as transport, scheduling appointments, conflicts with school engagements, and being in a period of transition into adulthood where they experience structural changes (e.g., health insurance). Transport was the only reported challenge for older adult women for follow-up. Both age groups preferred longer follow-up periods to refill their PrEP prescriptions and to obtain PrEP from a trusted physician (e.g., OBGYN). Both groups of Black women expressed a preference for PrEP to be advertised through diverse means including social media campaigns, sexual health forums, peer groups on college campuses, and by featuring Black women in PrEP commercials. Conclusions To improve PrEP equity and initiation among current and emerging PrEP modalities, it is crucial to better integrate the lived experiences and preferences of Black cisgender women and enhance their representation in PrEP messaging.