If you’re an EU citizen, you and your family will be able to apply to the EU Settlement Scheme to continue living in the UK after 30 June 2021. If your application is successful, you’ll get either settled or pre-settled status.

You may be able to stay in the UK without applying – for example, if you’re an Irish citizen or have indefinite leave to remain (ILR).

The EU Settlement Scheme will open fully by 30 March 2019. You may be able to apply now if you meet the criteria. The deadline for applying will be 30 June 2021 (NB: The deadline for applying will be 31 December 2020 if the UK leaves the EU without a deal).

When you choose to apply may depend on your circumstances.

More here:  https://www.gov.uk/settled-status-eu-citizens-families