Air Ambulance Affordability Act of 2019 This bill establishes requirements for health insurance plans and air ambulance service providers with respect to payments for air ambulance services provided to insurance plan holders with emergency medical conditions. First, a health plan must impose no more than the in-network rate for air ambulance services even if the provider of such services is out-of-network. The cost-sharing responsibility of the plan holder also must be the same as if the services were provided in-network and must count toward the plan holder’s deductible. Further, the health plan must reimburse the air ambulance provider for such services in the amount under applicable state laws for determining medical service rates or, in the absence thereof, a commercially reasonable amount as determined by a certified independent dispute resolution process. Additionally, out-of-network air ambulance service providers are subject to civil penalties if such a provider holds a plan holder liable for any amount above the plan holder’s cost-sharing responsibility based on the appropriate determined rate for the service, unless the provider obtains informed written consent from the plan holder.