This will vary based on state or county. In WI the health department really really wants people to get their 2nd dose at the same site because that is how they plan inventory and shipping schedules. The scripting they use is "you have a reserved 2nd dose" at the original site (although the sites are not actually holding back doses, the 2nd doses are calculated into future doses shipped). In order to make this work each site is supposed to schedule the 2nd dose right after administering the first. If someone shows up who had a first dose elsewhere, we are supposed to encourage them to return to their original site because "that is where your reserved 2nd dose has been shipped". Ultimately if that isn't possible for them we are supposed to give the 2nd dose.One thing that helps is that you don’t have to get the second dose at the same place as the first; just make sure you get your dose card. Again, booking the second dose was a lot easier.