If you hold a valid M-card or Annex 56 (which proves you applied for the M-card), you may reside in Belgium for more than 90 days. Your initial M card will be valid for 5 years and is renewable.
To maintain your M-card, you should ensure you continue to fall into one of the following categories:
Employed, self-employed or a student; or
Can demonstrate adequate means of subsistence and have health insurance; or
You are a family member of someone who meets these conditions.
You can switch between the above categories. Therefore, if your situation changes (for example, you lose your job or get divorced) you can still maintain your M-Card, as long as you can demonstrate adequate means of subsistence and proof of health insurance.
After five years of continuous legal residence in Belgium you are entitled to permanent residence. Both periods before and after the transition period are taken into account. If you have a permanent right of residence, you will have received an M-card which indicates this. The M-card for holders of permanent residence has a validity of 10 years and is renewable.
Holders of a regular M card can be absent from Belgium for up to one year without negative effects on their residence status. Holders of an M card with permanent right of residence can be absent for up to five years without risk of losing their residence status.