Disability contributions: the Constitutional Court censures the full-time equivalent denominator

The Constitutional Court has ruled that Article 142, § 4, of the program law of December 27, 2021 violates Articles 10 and 11 of the Constitution insofar as it calculates the denominator of the invalidity entry ratio in full-time equivalents. Judgment No. 60/2026 of May 21, 2026 is published in the Belgian Official Gazette No. 254 of November 6, 2026, p. 59614, under reference C − 2026/007416. It answers seven preliminary questions posed by the French-speaking Labour Court of Brussels.

A contribution targeting excessive invalidity flows

The regime in question is set out in Articles 139 to 148 of the program law of December 27, 2021, as amended by the law of November 20, 2022 and the law of December 21, 2023. It has been applicable since January 1, 2022. The quarterly accountability contribution is due from employers who fall under the law of December 5, 1968 on collective labour agreements and joint committees, employ at least 50 workers, and exhibit an excessive flow of workers entering invalidity.

Its key parameters, as recalled in the judgment:

• a rate of 0.625% of the contributable remuneration declared to the National Social Security Office (ONSS) for quarter Q-1;
• a calculation performed by the ONSS based on invalidity admission data provided by the National Institute for Health and Disability Insurance (INAMI), collected via debit note in Q+2;
• “X” and “Y” factors set at 2 and 3 by the Royal Decree of December 13, 2022, compared against sectoral and general private sector benchmarks;
• a threshold of three workers who entered invalidity during the reference quarters;
• exemptions for sheltered workshops, adapted work enterprises, social workshops, and maatwerkbedrijven.

According to the cited preparatory works, the contribution aims to “reorient structural deviations” and not to “collect a maximum of contributions.”

Numerator in headcounts, denominator in full-time equivalents

The fifth preliminary question concerned the situation of employers employing part-time workers. The Court notes that the invalidity entry flow ratio counts individual workers in the numerator, but total employment expressed in full-time equivalents in the denominator. A part-time worker entering invalidity therefore weighs as a full-time employee at the top of the ratio, while only counting for their fraction at the bottom.

The Court finds this choice reasonably justified regarding the numerator, the threshold of 50 workers, and the threshold of three entries: “the prevention of long-term incapacity for work and reintegration into work indeed concern each individual worker.” On the other hand, it finds it unjustified for the denominator. The ruling is clear: Article 142, § 4, violates Articles 10 and 11 “in that it provides that, to determine the denominator of the ratio referred to in Article 140, paragraph 2, of the same program law, total employment is calculated on the basis of the number of full-time equivalent workers.”

Six other grievances dismissed

For the remainder, the Court validates the bulk of the regime’s architecture: Articles 139 to 144 do not violate Articles 10 and 11 of the Constitution.

• Absence of exemption for the employer not responsible for the entries into disability: justification accepted.
• Threshold of 50 workers: objective criterion, within the broad margin of appreciation of the legislator.
• Calculation method as a percentage of remuneration: non-disproportionate burden.
• Consideration of only the NACE code of the main activity, without distinction by technical operating unit: justified.
• Exclusion of employers outside the scope of the Law of December 5, 1968: justified by the allocation of revenues to the existence security funds of the joint committees.

The judgment was rendered in French and Dutch on May 21, 2026, presided over by Pierre Nihoul, with Joséphine Moerman as second president, judges Michel Pâques, Danny Pieters, Willem Verrijdt, and Kattrin Jadin, president emeritus Luc Lavrysen, and clerk Nicolas Dupont. The Dutch version appears on p. 59621 and the German version on p. 59628 of the same issue.

A regime already repealed but still judged

The practical scope of the judgment is limited by the legislative calendar. Articles 139 to 148 are repealed as of April 1, 2026, by the Law of December 19, 2025, “implementing a reinforced return-to-work policy in case of incapacity for work,” which establishes an employers’ solidarity contribution concerning primary incapacity for work. Furthermore, the Law of January 14, 2026, modified, with effect from January 1, 2025, Articles 147/1 to 147/3 applicable to temporary work agencies and building cleaning. The Court specifies that these new provisions do not apply ratione temporis to the dispute pending before the referring court.

The impact remains concrete for employers of 50 or more workers whose litigation concerns prior periods: the calculation of the denominator in full-time equivalents, which artificially inflated the disability entry ratio for companies utilizing part-time work, is now devoid of a constitutional basis. Appeals based on this calculation point possess a powerful argument, while the contribution has already funded, via sectoral funds, prevention and reintegration measures for long-term sick employees.

Official source: Belgian Official Gazette (Moniteur belge) No. 254 of November 6, 2026, p. 59614, C − 2026/007416, excerpt from judgment No. 60/2026 of May 21, 2026, docket number 8420.