> For the complete documentation index, see [llms.txt](https://docs.finngen.fi/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.finngen.fi/working-in-the-sandbox/which-tools-are-available/atlas/detailed-guide/how-to-define-a-cohort-in-atlas/cohort-definitions/using-the-death-register-in-atlas.md).
# Using the Death register in Atlas
Please follow these instructions to use the Death register in Atlas:
* Click **Add criteria to group** button and select **Add Death.**
The next steps depend on whether you are using [standard or non-standard medical codes](/working-in-the-sandbox/which-tools-are-available/atlas/detailed-guide/code-sets-in-atlas.md) in your Concept Set.
### Using standard codes
* If you are using standard codes, click the button next to the **"a death occurrence from"** text and select your Concept Set.
* Save your cohort using the button.
### Using non-standard codes
* If you are using non-standard codes, first click **Add attribute** button and select **Add Cause of Death Source Concept Criteria**.
* Then click the button next to the **"Death Source Concept is"** text and select your Concept Set.
 
* Save your cohort using the button.