38 CFR §17.1515

1. (a)Electing non-VA care. A veteran eligible for the Veterans Choice Program under § 17.1510 may choose to schedule an appointment with a VA health care provider, be placed on an electronic waiting list for VA care, or have VA authorize the veteran to receive an episode of care for hospital care or medical services under 38 CFR 17.38 from an eligible entity or provider.
2. (b)Selecting a non-VA provider. An eligible veteran may specify a particular non-VA entity or health care provider, if that entity or health care provider meets the requirements of § 17.1530. If an eligible veteran does not specify a particular eligible entity or provider, VA will refer the veteran to a specific eligible entity or provider.