The U.S. abortion market has grown increasingly concentrated recently, while many states tightened abortion laws. Using data on abortion providers, I estimate an equilibrium model of demand, price competition, entry and exit, to capture the effect of regulation on industry dynamics. Estimates show regulations played an important role in determining the abortion market structure and evolution. Counterfactual simulations reveal increases in demand-aimed regulation were the most important observed factor in explaining recent abortion declines. Simulating Utah's regulatory regime nationally shows tightening abortion restrictions can increase abortions in equilibrium, mainly through tilting the competitive landscape toward low-price providers.