> ## Documentation Index
> Fetch the complete documentation index at: https://studies-guides.jaspari.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Geographic Scope

> Choose where your study recruits from: a radius around your site, a list or set of ZIP codes, specific states, or nationwide.

Every study has one geographic scope, set at the study level, that defines where volunteers must be located to match.

## Scope types

<CardGroup cols={2}>
  <Card title="Site Radius" icon="navigation">
    A radius around one of your assigned sites. Fits a study where volunteers need to travel to a physical location.
  </Card>

  <Card title="ZIP Radius" icon="map-pin">
    A radius around a specific ZIP code, independent of any site. Useful when your recruitment area isn't centered on a physical location.
  </Card>

  <Card title="ZIP List" icon="list">
    A specific, hand-picked list of ZIP codes.
  </Card>

  <Card title="States" icon="landmark">
    One or more entire states.
  </Card>

  <Card title="Nationwide" icon="globe">
    The entire United States, typically used for virtual studies or very broad recruitment.
  </Card>
</CardGroup>

## How geography affects price

Your recruitment area's population factors into your study's per-lead price: a smaller population inside your chosen scope means a larger geography surcharge, since a smaller pool is harder to recruit from. See [Pricing](/billing/pricing) for how this combines with your eligibility criteria to set the final price.

## Adjusting scope

You can change your geographic scope any time the study is in draft, active, or paused. Common reasons to adjust:

* Your current radius or ZIP list isn't yielding enough volunteers.
* A protocol amendment changes how far volunteers can reasonably travel.
* You're expanding from a single-state to a nationwide virtual arm.

If the study is in draft, changing the recruitment area updates the live price estimate immediately. If the study is active or paused, the change recalculates its locked-in price right away. Volunteers already matched before the change retain their original charged price.


## Related topics

- [Launch Your First Study](/getting-started/quickstart.md)
- [Studies Overview](/studies/overview.md)
- [Setup and Launch](/studies/setup-and-launch.md)
- [Roles & Permissions](/sharing/roles-permissions.md)