Short answer: The ACA-required preventive services are standardized and must be covered at no cost in-network on all non-grandfathered plans. Plans can differ in extra wellness perks, and out-of-network preventive care may carry cost-sharing.
The core list of preventive services is set federally, so every non-grandfathered plan must cover the same screenings, immunizations, and wellness visits at $0 when you stay in network. Where plans differ is at the margins: some add extra wellness benefits or programs, and preventive care received out of network may not be free. So the baseline is consistent, but it’s worth confirming a service is on the required list and delivered in network to get it at no cost.