How to Add a User to a Group on Linux (and Manage Users)

To add a user to a group on Linux, run sudo usermod -aG groupname username, for example sudo usermod -aG www-data alex. The -a (append) flag keeps the user’s other groups. The change applies the next time the user logs in; check it with id alex. The same command works on Ubuntu, Debian, AlmaLinux and Rocky Linux.

Difficulty	Time	Works on	Needs
Beginner	5 minutes	Ubuntu 22.04 / 24.04, Debian 12 / 13, AlmaLinux / Rocky 9 / 10	sudo or root access

Before you start

Connect with SSH as root or a sudo user. Root can leave out sudo.
A group is a named set of users. Files have an owner and a group, and permissions decide what each can do. Putting users in a group is how you let several people share files.

How to add a user to a group

Add the user

sudo usermod -aG developers alex

To add several groups at once, separate them with commas: sudo usermod -aG developers,www-data alex.

Check the result

id alex

Expected output:

uid=1001(alex) gid=1001(alex) groups=1001(alex),27(sudo),1002(developers)

The user must log out and back in (or start a new SSH session) before the new group applies. Running processes keep their old groups.

Never leave out -a. sudo usermod -G developers alex replaces all of alex’s extra groups with just developers, which can remove sudo access. Also don’t add normal users to sudo, wheel, root, docker or disk: each of these gives root-level control.

How to create and delete groups

sudo groupadd developers     # create a group
getent group developers      # show the group and its members
sudo groupdel developers     # delete a group (it must not be anyone's primary group)

How to remove a user from a group

sudo gpasswd -d alex developers

Expected output:

Removing user alex from group developers

How to create users

Ubuntu / Debian
AlmaLinux / Rocky

sudo adduser alex

adduser asks for a password and creates /home/alex.

sudo useradd -m alex
sudo passwd alex

Useful useradd options on any distribution:

Option	Effect	Example
`-m`	Create the home directory	`useradd -m alex`
`-s`	Login shell	`useradd -m -s /bin/bash alex`
`-G`	Extra groups	`useradd -m -G developers alex`
`-r`	System account for a service (no login, low UID)	`useradd -r -s /usr/sbin/nologin myapp`

How to list users and groups

getent passwd            # every account, one per line
getent passwd | cut -d: -f1   # just the user names
groups alex              # groups of one user
getent group sudo        # members of one group

Accounts with a UID of 1000 or higher are usually people. Lower numbers are system accounts used by services such as www-data or mysql.

How to change, lock and delete users

Task	Command
Change a password	`sudo passwd alex`
Change the login shell	`sudo usermod -s /bin/bash alex`
Rename a user	`sudo usermod -l alexandra alex` (the home folder keeps its name unless you also use `-d /home/alexandra -m`)
Lock an account (password login stops)	`sudo passwd -l alex`
Unlock it	`sudo passwd -u alex`
Expire an account fully (also blocks SSH keys)	`sudo usermod --expiredate 1 alex`
Delete a user, keep files	`sudo userdel alex`
Delete a user and home directory	`sudo userdel -r alex`

userdel -r deletes the user’s home directory and mail spool permanently. Copy anything you need first. Make sure the user has no running processes (pgrep -u alex) before you delete the account.

passwd -l only blocks password logins. A user with an SSH key can still log in. To stop all logins, expire the account with usermod --expiredate 1 or remove the key from ~/.ssh/authorized_keys.

How to check it worked

Start a new SSH session as the user and run id. The new group must appear in the list. To test file access, create a shared folder:

sudo mkdir -p /srv/shared
sudo chown root:developers /srv/shared
sudo chmod 2775 /srv/shared

Any member of developers can now create files in /srv/shared. The 2 (setgid) makes new files inherit the developers group.

Frequently asked questions

Why doesn’t my new group work yet?

Group membership is read at login. Log out and back in, or run newgrp developers to start a shell with the new group straight away.

What is the difference between a primary and a secondary group?

The primary group (usually named like the user) is the group new files get. Secondary groups, added with usermod -aG, give extra access. id shows the primary group as gid= and all groups under groups=.

How do I give a user admin (sudo) rights?

Add them to sudo on Ubuntu/Debian or wheel on AlmaLinux/Rocky. See how to create a sudo user.

Can I edit /etc/passwd or /etc/group directly?

You can, but a typo can lock everyone out. Use usermod, gpasswd and groupadd, or sudo vigr and sudo vipw, which lock the file and check it.

VPS and dedicated server guides

Every server guide in one place.

Create a sudo user

Give a user admin rights.

File permissions explained

chmod and chown in plain words.

Who is logged in

Check sessions and login history.

Checked against the usermod, useradd, userdel, gpasswd and passwd man pages from the shadow-utils project on 4 November 2026; commands tested on Ubuntu 24.04 LTS. Commands can differ on other distributions or releases.

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Last Updated: November 2026

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How to Add a User to a Group on Linux (and Manage Users)

Before you start

How to add a user to a group

How to create and delete groups

How to remove a user from a group

How to create users

How to list users and groups

How to change, lock and delete users

How to check it worked

Frequently asked questions

Why doesn’t my new group work yet?

What is the difference between a primary and a secondary group?

How do I give a user admin (sudo) rights?

Can I edit /etc/passwd or /etc/group directly?

VPS and dedicated server guides

Create a sudo user

File permissions explained

Who is logged in

Need Extra Help?

Save on Your Hosting

​Before you start

​How to add a user to a group

​How to create and delete groups

​How to remove a user from a group

​How to create users

​How to list users and groups

​How to change, lock and delete users

​How to check it worked

​Frequently asked questions

​Why doesn’t my new group work yet?

​What is the difference between a primary and a secondary group?

​How do I give a user admin (sudo) rights?

​Can I edit /etc/passwd or /etc/group directly?

​Related guides

VPS and dedicated server guides

Create a sudo user

File permissions explained

Who is logged in

​Need Extra Help?

​Save on Your Hosting

Before you start

How to add a user to a group

How to create and delete groups

How to remove a user from a group

How to create users

How to list users and groups

How to change, lock and delete users

How to check it worked

Frequently asked questions

Why doesn’t my new group work yet?

What is the difference between a primary and a secondary group?

How do I give a user admin (sudo) rights?

Can I edit /etc/passwd or /etc/group directly?

Related guides

Need Extra Help?

Save on Your Hosting