When are you faced with a relapse?
You are faced with a relapse when a worker who has returned to work becomes unable to work again due to the same illness.
The concept of relapse is based on three essential elements that you must verify:
-
The cause of the new incapacity (same illness)
-
The effective return to work between two periods of incapacity.
-
The period between the end of the first incapacity and the beginning of the new one must be considered.
If these conditions are met, the new incapacity is not seen as a "new" illness, but rather as a legal extension of the previous incapacity.
Read more: « When is there a question of relapse? »
What are the consequences of the relapse?
As an employer, it is important to correctly identify a relapse situation to determine whether you need to pay a new guaranteed salary.
In the case of a relapse, the worker is not entitled to a new guaranteed salary at your expense. Only the part of the guaranteed salary that has not yet been used during the first incapacity remains due, if applicable. You must check whether the guaranteed salary has already been fully paid during the first period of incapacity.
What change applies to the relapse period from 1 January 2026?
Until 31 December 2025, the relapse had to be assessed within a period of fourteen days following the end of the previous incapacity.
Since 1 January 2026, this period has been extended to eight weeks.
This extension of the relapse period reduces the number of situations in which you must start a new period of guaranteed salary.
What transitional rules must you apply?
As an employer, you must follow these transitional rules:
-
The new rules apply only to incapacities starting after 1 January 2026
-
A period of guaranteed salary already in progress before this date is not interrupted (the old rules still apply)
-
An incapacity that began before 1 January 2026 remains subject to the fourteen-day relapse period
Example 1
The worker is incapacitated from 1 November 2025 to 30 November 2025. They return to work on 1 December 2025. They fall back into work incapacity due to the same illness on 10 January 2026.
This new work incapacity occurs within eight weeks following the end of the previous incapacity. You do not need to start a new period of guaranteed salary. Before 2026, you would have had to pay the guaranteed salary again.
Example 2
The worker is incapacitated from 1 November 2025 to 30 November 2025. They return to work on 1 December 2025. They fall back into work incapacity due to the same illness on 5 February 2026.
More than eight weeks have passed since the end of the previous incapacity. This is not a legal relapse. You must start a new period of guaranteed salary, according to the rules applicable to the worker's status.
Comparative example
Your female worker is incapacitated from 15 December 2025 to 31 December 2025. She returns to work on 1 January 2026. She falls back into work incapacity due to the same illness on 5 February 2026.
| Before 1 January 2026 | Since 1 January 2026 | |
|---|---|---|
| Applicable relapse period | 14 days | 8 weeks |
| Time elapsed since the end of work incapacity | More than 14 days | Less than 8 weeks |
| Legal qualification | New work incapacity | Relapse |
| Guaranteed salary | Again due | Not due |
| Consequence for you as an employer | New salary cost | No new guaranteed salary |
Entry into force
The extension of the relapse period to eight weeks came into force on 1 January 2026.
What does Securex do for you?
For any additional information or questions regarding the relapse rules, you can contact your Legal Advisor at myHR@securex.be
You can also consult our sheet here.
Source
- Law of 19 December 2025 implementing a strengthened return-to-work policy in case of work incapacity
