Sick employees in Luxembourg: the 77 days, the sick note and your duties as an employer

When must a sick employee notify the employer and hand in a medical certificate?

The employee informs the employer on the very day of the absence, orally or in writing, personally or through someone else, then hands in a medical certificate confirming the incapacity and its expected duration no later than the 3rd day of absence (Art. L.121-6 of the Labour Code). According to the Labour and Mines Inspectorate (Inspection du travail et des mines, ITM), this deadline runs from the first day of absence, Sundays and non-working days included, and expires at midnight. So a part-time employee who does not work on Mondays and falls ill on a Monday informs the employer on Tuesday, the first day of absence, and hands in the certificate by midnight on Thursday.

Without a certificate, the absence is unjustified and pay may be withheld; once it is handed in, the whole period it covers is justified. A collective agreement or internal rules may waive the certificate for 1 or 2 days. If a certificate arrives late, take advice before making any decision. The electronic certificate (eCIT), which the employer receives through MyGuichet.lu, does not change these deadlines.

How does the 77-day rule work?

The employer continues to pay the full salary and contractual benefits until the end of the calendar month in which the 77th day of incapacity falls, over a reference period of 18 consecutive calendar months (Art. L.121-6; 18 months since 1 January 2019). The CNS then pays the sickness benefit.

• Calendar days: weekends and public holidays included.
• Only days at the employer's expense: sickness, accident (including at work), incapacity during the probationary period. Days paid or refused by the CNS, maternity, the exemption from work of pregnant or breastfeeding women, and family leave, end-of-life care leave and adoption leave do not count.
• Rolling window: the 18 calendar months before the month being examined.
• Test on the 1st of each month: below 77 days, the employer pays that month's sickness, until the end of the month in which the 77th day is reached; at 77 days or more, the CNS pays from the 1st. If the 77th day falls on the last day of the month, the employer's obligation ends that day.
• One counter per employer: it restarts at zero with a new employer.

In practice, salary continuation lasts 11 to 15 weeks (guichet.lu). As soon as the CNS informs you that it is taking over, stop paying the salary. Guichet.lu provides an Excel calculation file.

Which salary must be continued?

If the employee's schedule was set at least until the end of the month: base salary plus the bonuses, supplements and premiums that schedule provided for (planned Sunday, night or public holiday work). Otherwise: the average daily pay of the previous 6 months (12 months if pay varies widely), excluding overtime, gratuities and expenses. ITM example: €4,000 ÷ 173 × 8 hours, i.e. about €185 a day.

Worked example: calculating the 77 days over 18 months

Full-time employee, Monday to Friday, employed since 2020, no sick leave before 2026. Three absences: Monday 12 to Friday 16 January 2026 (5 calendar days), Monday 2 March to Sunday 31 May 2026 (91 days), Monday 5 to Wednesday 7 October 2026.

The employer pays 96 days in 2026 (5 in January, 91 from March to May), because it pays until the end of the month of the 77th day, not just until the 77th day. From June 2026 to September 2027, any sickness of this employee is paid by the CNS, even after returning to work, because the window still contains more than 77 days paid by the employer. In October 2027, March 2026 leaves the window: the counter drops to 61 days and the employer takes over again.

The official example of the Joint Social Security Centre (Centre commun de la sécurité sociale, CCSS) follows the same logic: the employer pays until the end of April 2020, the month of the 77th day, the CNS from May 2020, then the employer again from September 2021.

Can you dismiss a sick employee in Luxembourg?

Not for up to 26 weeks from the start of the incapacity: an employer that has been notified or holds the certificate may neither give notice of termination, even for serious misconduct, nor invite the employee to a pre-dismissal interview (Art. L.121-6). A dismissal notified in breach of this protection is unfair.

• Calculation: in calendar days, i.e. 182 days. A return to work followed by a new illness opens a new 26-week period. The right to dismiss returns on the first working day after the last day covered by the certificate.
• Exceptions: incapacity resulting from a crime or offence in which the employee deliberately took part; notice or certificate received after the dismissal letter or interview invitation, except in the case of emergency hospitalisation (certificate within 8 days).
• Probationary period: sickness suspends it and extends it accordingly, by up to one month, and the protection applies (Art. L.121-5).
• After 26 weeks: the employer may dismiss following the normal procedure. If it does not, it tops up the CNS benefit to the net salary, at the latest until the end of the 12 months following the month in which the incapacity began (ITM).
• Repeated absences: if they disrupt the business, they may justify dismissal with notice, on return or after the 26 weeks, except where they result from an accident at work or an occupational disease (ITM).

What does the Employers' Mutual Insurance Scheme reimburse and what must be reported each month?

The Employers' Mutual Insurance Scheme (Mutualité des employeurs, MDE) reimburses 80% of the gross continued salary (base pay and supplements paid monthly in cash), plus employer pension, sickness and accident contributions, in proportion to the hours of incapacity in the month. The reimbursement is 100% for sickness or an accident during the probationary period (first 3 months at most), family leave, end-of-life care leave, quarantine or isolation (Art. 54 of the Social Security Code and Art. 14 of the MDE statutes).

No return, no reimbursement: within 10 days after each month, the employer reports to the CCSS, together with salaries, every period of incapacity (dates, type, hours claimed), including those where it continues to pay the salary. Inconsistent data, such as more hours of absence than hours reported, block the reimbursement.

The financial absenteeism rate compares the reimbursements received with the contributory payroll over 3 financial years (thresholds from the MDE statutes as coordinated in 2021). Accidents at work, occupational diseases and maternity, among others, are left out. A new member starts in class 2.

After the 77 days: CNS benefit, 78 weeks and end of contract

The CNS sickness benefit is due from the first working day of declared incapacity but suspended while the salary is continued; the employee must therefore report the incapacity to the CNS even during salary continuation (Art. 11 of the Social Security Code).

• Amount: the highest base pay of the 3 months before payment, plus the average of supplements and extras over 12 months, excluding overtime, gratuities and benefits in kind (Art. 10). Nothing beyond age 68.
• Cap of 78 weeks out of 104: all incapacity due to sickness, accidents at work or occupational disease counts towards it, whoever pays, except maternity and the exemption from work of pregnant or breastfeeding women; the CNS simulates the end date as the threshold approaches.
• Automatic end of contract: without dismissal, on the day this entitlement runs out, or on the day of the decision granting an invalidity pension (Art. L.125-4). Pay in lieu of untaken leave remains due.
• Fixed-term contracts, temporary work and notice periods: the employer only pays until they end; the CNS then takes over if the employee has been insured for 6 months without interruption and receives neither pay nor a replacement income.
• CNS refusal, for example if the Medical Control Service (Contrôle médical) finds the employee fit for work: salary continuation ends, even if new certificates follow; the protection ends when the 40-day appeal period expires, unless an appeal is lodged, and refused days count neither towards the 77 days nor towards the 78 weeks.

Checks, permitted outings and return to work

The employer may ask the CNS to check that the employee is at home or at the declared address, between 8 am and 9 pm from the first day, cross-border workers included (a new request is possible 30 days later). As the certificate is only a rebuttable presumption, the employer may also have the employee examined by a doctor of its choice, at its own expense; repeated refusal without a valid reason forfeits the protection.

• Outings: from day 1 to day 5, only for care, medicines or tests, Medical Control Service appointments and, after informing the CNS in advance, a meal out; from day 6, if the medical certificate allows outings, from 10 am to 12 noon and from 2 pm to 6 pm (CNS statutes). A stay abroad requires the CNS's prior approval.
• Return after more than 6 weeks of uninterrupted absence: the employer informs the occupational health doctor (Art. L.326-6).
• Gradual return to work for therapeutic reasons: with the employer's agreement and a prior CNS decision; the period counts towards the 78 weeks.
• Sickness during leave: days covered by a certificate are not deducted from leave (Art. L.233-11); see the Annual leave page.
• Health data: a special category (Art. 9 of the General Data Protection Regulation, GDPR); keep certificates separately, with restricted access.

Common mistakes

• Counting in working days. The 77 days are calendar days, weekends and public holidays included.
• Stopping pay on the 77th day. The employer pays until the end of the month in which that 77th day falls.
• Adding days paid by the CNS to the counter, or forgetting that it restarts at zero with a new employer: only days at the employer's expense add up.
• Confusing the deadlines. To the employer: 3rd day of absence, in calendar days, until midnight. To the CNS: 3rd working day.
• Dismissing too early on return. The right to dismiss only returns on the first working day after the last day covered, and each new absence after a return to work reopens 26 weeks of protection.
• Continuing to pay after a CNS decision. A refusal or a takeover by the CNS ends salary continuation: the employer does not have to stand in for the CNS.

Your checklist

• Record the date, time and channel of each notice, then check on the evening of the 3rd day that the certificate has arrived.
• Activate the "salaires et incapacités de travail" (salaries and incapacity for work) domain in your MyGuichet.lu professional space and download electronic certificates promptly.
• Report every period of incapacity to the CCSS within 10 days after each month, including those paid by the employer.
• Track each employee's 77-day counter and act promptly on CNS notices: takeover, refusal, restored entitlement.
• Block any dismissal or interview letter during the 26 weeks of protection.
• Inform the occupational health doctor when an employee returns after more than 6 weeks of uninterrupted absence.
• Prepare for the automatic end of contract as 78 weeks approach: final settlement, pay in lieu of untaken leave, end-of-contract documents.
• Keep certificates separately, with restricted access and a defined retention period.

Frequently asked questions

Official sources

• Labour Code, consolidated version of 26 July 2026, Art. L.121-6 (Legilux, in French)
• Social Security Code, consolidated version of 1 January 2026 (Legilux, PDF, in French)
• CNS, sickness benefit for employees, employers' page (in French)
• CCSS, example calculation of the 77-day threshold and of who pays (in French)
• Employers' Mutual Insurance Scheme, statutes, coordinated version (in French)
• CCSS, social parameters and contribution rates: minimum wage, ceiling, MDE rates (in French)
• CNS, reporting an employee's incapacity and the electronic certificate, employers' page (in French)
• CNS, permitted outings during sick leave, employers' page (in French)
• Guichet.lu, salary continuation during incapacity for work (in French)
• ITM, FAQ D6a1: deadline for informing the employer (in French)

This guide sets out the general rules in force on 5 October 2026. It is not legal advice for your situation (collective agreement, sector, employee status).