L4 under new rules. Working while on sick leave in practice.

On January 12, 2026, a law was published in the Journal of Laws amending the rules for working under L4 system. For employers, this represents a significant change in absenteeism management. The new regulations introduce, among other things, the ability to legally work for one payer while on sick leave with another. How will the new definitions of “incidental activities” and “paid work” impact the functioning of companies? We explain. 

Working during L4? Exceptional situations 

The key change is the departure from the principle that L4 must cover all professional activities of the insured person at the same time. 

New sick leave – how is it supposed to work? 

Pursuant to the act announced on January 12, 2026, from January 1, 2027, new rules for issuing certificates for persons with at least two insurance titles (e.g. working for two different employers or combining full-time employment with a contract of employment) will come into force. 

Currently, the L4 automatically excludes work at any of these locations. Following the changes, a physician, at the employee’s request, will be able to issue an exemption for only one payer of contributions, provided the type of work performed at the other employer allows it. 

Key criteria for accepting work on L4: 

• Nature of Duties. As the Act states: Access inconsistent with the purpose of the leave in question includes any activity that hinders or prolongs the treatment or recovery process, excluding normal daily activities or incidental activities. Therefore, for example, an academic lecturer who has suffered an injury that prevents them from commuting to the university may be on L4 as part of their full-time position while continuing to deliver lectures online under an agreement with a second institution. 

• Information obligation. An employee is obligated to notify the payer of contributions for which they intend to work about any sick leave they hold for other reasons. 

• Transparency. The new regulations introduce precise definitions of “gainful employment” (gainful employment is any activity of a gainful nature, regardless of the legal relationship underlying its performance, excluding incidental activities that must be undertaken during a period of sick leave due to significant circumstances. A significant circumstance cannot be an employer’s instruction) and “activity inconsistent with the purpose of the sick leave.” This is intended to help prevent abuse. 

Tip for employers: It’s worth updating internal procedures for circulating information about incapacity for work so that staff know how to verify employee declarations of “partial” incapacity for work with other payers. 

Table: Comparison of L4 rules – current status vs. new regulations (from 2027) 

The table below illustrates the most important differences in the approach to an employee with two sources of income (e.g. two full-time jobs or a full-time job and a contract). 

Daily activities and L4 control 

In the first half of April 2026 (i.e., three months after the Act’s publication in the Journal of Laws), regulations designed to minimize the risk of uncertainty during sick leave audits will come into force. The amendment introduces a catalogue of permissible activities, incidental activities, that an employee can perform while on sick leave without fear of losing sick leave benefits. 

L4 – what changes in practice? 

Until now, going grocery shopping or attending a short meeting has been a source of dispute with the Social Insurance Institution (ZUS). The new law explicitly allows for the performance of daily activities, which in practice means that 

• going to the pharmacy, grocery shopping or a short recreational walk (unless the doctor recommended bed rest) will no longer be grounds for questioning the sick leave. 

• low-intensity professional activity may be allowed, new the regulations allow occasional and necessary activities, such as answering an important work call or attending a key online meeting, provided they are incidental and do not hinder recovery. 

Benefits for employers, i.e. fewer legal disputes 

Clarifying the issues described above in the amended Act is important from the point of view of employers and HR departments and may mean, among others: 

• fewer appeals against inspection results; 

• more transparent rules for control committees established within companies; 

• better relationships with employees, based on mutual trust and the real life needs of sick people. 

Changes in L4. How can we help? 

Given the upcoming changes to the L4 system and new reporting obligations, it’s worth investing in tools that guarantee full control over data flow within the company. We offer access to the Automatic Working Time and Attendance System (RCP System), which is an integral part of our proprietary Asistar platform. 

The Asistar RCP system is a solution fully adapted to the specifics of Polish law, automating accounting and billing processes. The tool was designed with three user groups in mind: 

• HR and personnel departments – automation allows for the immediate consideration of sickness absences and their impact on payroll. 

• For management staff – it provides ongoing insight into the team’s availability and facilitates work planning in the face of the new “selective” L4 rules. 

• Employees – provides transparent insight into their working time and absence status. 

Ensure compliance with the new regulations now, contact us!