From April 13, 2026, all employers will gain the right to independently verify medical certificates, ending the previous 20-employee limit that restricted small businesses.
Background: Current L4 Control Rules
Today, there is a clear boundary: only employers reporting to sickness insurance for more than 20 people can independently check the proper use of medical certificates. Smaller entrepreneurs can only turn to the Social Insurance Institution (ZUS) to conduct a check – and wait for its result.
Changes from April 13, 2026
From April 13, 2026, this will change. The amendment extends the right to control to all contribution payers paying sickness benefits, regardless of the number of employees. This concerns control for the payment of sickness benefits as mentioned in Art. 92 of the Labor Code. It is precisely the employer – during the first 33 days of illness per year (14 days for employees 50+) – who finances this benefit.
Why Only Large Companies Could Previously Control L4
In practice, the previous system meant that for a large corporation, one absence is often a matter of schedule reorganization. In a small firm, however, it can cause real paralysis. It is precisely this argument that entrepreneurs have been raising for years. Mikołaj Zając, president of the advisory firm Conperio specializing in absenteeism issues, points out that in small workplaces, a single absence can trigger a domino effect: the need for substitutes, overtime for other employees, delays in fulfilling orders.
What Employers Can and Cannot Do During L4 Checks
Employees’ biggest concern is whether the new regulations mean arbitrariness or “hunting” for sick people. The control of the proper use of L4 concerns only checking whether the certificate is used according to its purpose – that is, whether the employee does not perform paid work during illness or does not use the certificate in a manner contrary to the doctor’s recommendations.
ZUS will still make decisions in controversial cases. The employer does not replace the pension institution – but gains a verification tool that it did not have before.
Impact on Small Businesses: Costs and Obligations
For an entrepreneur employing several or a dozen people, the change has a very concrete dimension – financial and organizational. Sickness benefits for the first weeks of absence are financed from the employer’s funds. The new regulations may increase the sense of control over costs, limit potential abuses, and level the playing field between large and small entities. However, experts emphasize that the proper application of the regulations will be crucial.
Who Benefits and Who Is Unaffected
Small and medium-sized enterprises will gain from the change, as will entrepreneurs who have been struggling with absenteeism issues. The situation will not change for large corporations that already had this right. It is difficult to speak of a “loss” on the part of employees, as the change does not introduce new sanctions, but only extends the circle of entities entitled to control.
Potential for Further L4 Reforms
The discussion about abuses of medical certificates returns cyclically. On one hand, there are data on increasing sickness absence, on the other – arguments about employee overload and deteriorating public health. Extending the right of control to all contribution payers may be the first step to further systemic changes. For now, however, the amendment concerns only the issue of control competencies.



