Sex-steroid hormones powerfully influence internal states, mood, and social drives. In many species, including mice, females exhibit increased sexual receptivity during the peri-ovulatory phase following an estrogen surge. However, we lack understanding of how these hormones alter neural computations to regulate social behaviors, particularly their effects on neural dynamics in key regions for top-down control of social choice, such as the medial prefrontal cortex (mPFC). One potential, but unexplored role of the estrogen surge is to enable persistent neural states to facilitate costly behaviors during the reproductive window. To test this, here we manipulate estrogen levels in females across a multi-day social choice paradigm. We quantify moment-to-moment behavioral changes based on features from multi-animal pose tracking using 3D-SLEAP-Anipose, alongside chronic Neuropixels recordings from all mPFC subdivisions longitudinally across long-term hormone shifts. Female subjects reversibly change their social preference from females to males following estrogenic surge. Interestingly, higher estrogen levels also lead to more persistent behaviors. Using a hidden Markov model to segment the mPFC population activity in an unsupervised manner reveals neural state sequences that govern the cortical dynamics and predict behavioral state transitions revealing differences across estrogenic states. Dimensionality reduction and latent-space analyses suggest distinct ensembles in mPFC encoding male, female, and self-directed behaviors, and the ability to decode these states is significantly improved in the high estrogen states. Tracking day-to-day single-unit identity reveals increased spontaneous spiking on high-estradiol days. Surprisingly, we observe a decrease in units responsive to males compared to females after estrogen surges, indicating potential disinhibitory mechanisms. Crucially, the estrogen surge reduces representational drift in social tuning and enhances functional connectivity within similarly tuned ensembles. Together, our work demonstrates that sex steroid hormones significantly reshape female social preference and choice persistence by remodeling cortical dynamics, cellular properties and neural coding of social interactions.