Undermining the Evidence Value of the Medical Certificate of Incapacity for Work

Judgment of the Lower Saxony Regional Labor Court dated November 19, 2025 – Case No. 8 SLa 372/25

In labor law, disputes frequently arise when employees submit a medical certificate of incapacity for work (AU) after giving notice of resignation (or in close temporal proximity to it) and demand continued payment of wages. Employers often doubt in such situations whether there was actually a work-related incapacity due to illness. The Lower Saxony Regional Labor Court (LAG) has, in its judgment dated November 19, 2025 (Case No. 8 SLa 372/25), clarified the requirements for the evidentiary value of the AU certificate in a particularly contentious case group and specified the standards for an “undermining” of the evidentiary value.

The legal basis for continued payment of wages is § 3 para. 1 sentence 1 Continuation of Remuneration Act (EFZG): If an employee is unable to work due to illness, without it being their fault, they are generally entitled to continued payment of wages for up to six weeks. The medical certificate of incapacity for work regularly serves as a central piece of evidence. According to labor court jurisprudence, it generally holds significant evidentiary value. However, this evidentiary value is not “unassailable”: It can be undermined by concrete, objective circumstances. Consequently, the burden of presentation and proof can shift to the detriment of the employee.

Sick leave and resignation on the same day: Close temporal connection as a warning signal

The LAG Lower Saxony decided that the evidentiary value of an AU certificate might be considered undermined if the employee is certified as incapacitated and simultaneously declares the termination of employment on the same day. According to the court, the sequence of events (whether the resignation or the sick leave occurs first) is not decisive. What matters more is the close temporal connection of both events, which, from an objective observer’s perspective, can raise doubts about whether the certified incapacity for work actually existed.

Uninterrupted AU until the contract ends: “perfectly matched” duration as another point of doubt

Particularly significant in the case under decision was that the AU certificates were uninterrupted until the end of the employment relationship, thus “perfectly matching” the period until termination. Such a situation can, according to jurisprudence, be suitable to further weaken the evidentiary value—especially if additional circumstances suggest a strategic use of sick leave. Important: This is not a blanket assumption but an assessment of specific indications in each case.

The Case Before the Lower Saxony LAG

In the underlying proceedings, the plaintiff had been employed by a building cleaning company since 2018. According to her statements, she had felt work-related overburdened for a longer period and reported psychological complaints (including sleep disturbances, exhaustion, anxiety). In August 2024, a doctor made a corresponding diagnosis and certified incapacity for work. The same day, the plaintiff gave notice of ordinary termination. Subsequently, she submitted additional AU certificates without time gaps until the employment ended in mid-September 2024.

The employer refused to continue payment, justifying this particularly with the simultaneous resignation and sick leave, as well as the conspicuously precise duration of the incapacity until the contract ended in their view. The plaintiff then filed a lawsuit for the outstanding wages.

Decision: Evidence Value Undermined – Claim Dismissed

While the plaintiff initially succeeded in the first instance before the Labor Court in Hanover, the LAG Lower Saxony reversed this judgment and completely dismissed the claim. According to the LAG, there was no entitlement to continued payment of wages.

The court primarily relied on the assumption that the evidentiary value of the submitted AU certificates had been undermined. The decisive factors were:

• the close temporal coincidence of sick leave and resignation on the same day (regardless of the order), as well as
• the uninterrupted, until the end of employment reaching, and thus “perfectly matched” certified incapacity for work.

Under these circumstances, in the LAG’s view, the AU certificate alone was no longer sufficient to prove the illness-related incapacity for work.

High Evidentiary Value – but Not Unlimited

The LAG also clarified that AU certificates generally represent strong evidence. Employers cannot contest them “out of the blue.” Concrete facts that raise serious doubts are required. These were precisely seen as present by the court here. The temporal proximity of resignation and sick leave could, by itself, cause doubt; the “perfectly matched” duration amplified this in the overall assessment.

Consequence of Undermining: Employees Must Further Substantiate Illness and Incapacity

If the evidentiary value is undermined, presenting the AU certificate as evidence is no longer sufficient. Then, in a dispute, the employee must further substantiate and prove the illness-related incapacity for work. Practically, this means that additional substantial statements may become necessary, such as about symptoms, course, treatment, and the specific impacts on work ability. The limits of data protection and the legitimate interests of the employee must always be observed; nevertheless, it remains their task to substantiate the facts that justify the claim if the AU “indicator” no longer holds.

In the decided case, the plaintiff failed to provide this additional proof. The court emphasized that it is insufficient if the treating doctor merely finds the patient’s statements plausible. What is required is a medical determination based on comprehensible medical examination and diagnosis. Especially in cases of psychological illnesses, concrete, comprehensibly documented findings regarding symptoms and functional impairment are crucial to sustainably justify the incapacity for work.

Practical Tips for Employers and Employees

For Employees: Employees who are pronounced incapacitated for work on the day of resignation (or immediately thereafter) and are on sick leave uninterrupted until the end of employment must expect the employer to contest the evidentiary value of the AU. It may then become necessary to more thoroughly substantiate the incapacity for work in legal proceedings and possibly use additional evidence.

For Employers: Doubts about an AU must be based on concrete indications. A mere feeling or assumption is not enough. However, if the evidentiary value is undermined by objective circumstances, continued payment of wages can be refused, provided no sufficient alternative convincing evidence of incapacity for work is presented in the proceedings. Employers should always carefully document the facts supporting their doubts.

Classification and Legal Additions

The judgment is in line with established jurisprudence that AU certificates generally hold high evidentiary value, but this can be undermined in individual cases by indicators. In labor law practice, the following indicator groups are particularly relevant:

• Incapacity for work immediately following conflicts, warnings, or notice of termination,
• Striking temporal “accuracy” of the sick leave matching the expiration of notice periods,
• contradictory behavior (e.g., activities that appear difficult to reconcile with the claimed specific incapacity for work),
• multiple similar patterns at short intervals (always depending on the individual case).

It is important that such constellations do not lead to general suspicion of employees on sick leave. What remains decisive is always the overall assessment of all the circumstances of the individual case.

Note: This article serves general informational purposes and does not constitute individual advice. Whether a sick leave retains its probative value or is undermined in a particular case depends on the respective circumstances.

MTR Legal Attorneys supports companies and employees with questions regarding continued pay, incapacity for work, and the enforcement or defense of claims in the employment relationship. Further information on employment law can be found on our website.

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