The National Health Fund (CNS) reported €6.2m in losses detected or prevented through its work on suspected fraud and abuse in 2025, according to its annual report released on Monday 20 July.

The CNS opened 652 new files, 16% more than a year earlier. Cases involving insured people made up 70% of the total, but healthcare providers accounted for 80% of the amount at stake.

The report described the files as potential cases and did not say fraud had been established in every one of them. They included suspected falsification, questionable billing and other possible abuses, as well as cases that led to repayments, regulatory proceedings or criminal convictions.

Among the new files were 134 involving sick notes bought online and 117 involving documents suspected of having been falsified. The CNS said forged sick notes, prescriptions or medical invoices used to obtain benefits could lead to repayment orders, fines and imprisonment.

Sick notes and provider billing

Five cases involving false proof of payment, falsified prescriptions or sick notes resulted in prison sentences in 2025, the report said. One person received a 12-month prison sentence, although the report did not identify the defendants or give the sums involved.

The fund also stepped up checks on physiotherapists. It examined whether practitioners complied with minimum treatment times and limits on the number of sessions they could provide each day.

The checks found significant breaches and led to repayment claims as high as €200,000. The report did not say whether each claim followed a finding of deliberate fraud, but said every bill had to identify the practitioner who carried out the treatment.

Six cases involving dentists were brought before the body that oversees compliance with social-security rules, the Commission de surveillance de la sécurité sociale, while another dentist was found by the social-security tribunal, the Conseil arbitral de la sécurité sociale, to have breached tariff and billing rules.

The case involved charging above permitted tariffs, improperly combining fees and spreading charges across several days. Five further cases involving dentists were referred to prosecutors, and the CNS said its work on questionable billing would continue in 2026.

Care providers agree €21.8m repayments

Separate checks of long-term care providers led to €21.8m in agreed repayments during 2025.

The annual reviews assessed whether providers had enough suitably qualified staff to deliver all the care for which they claimed reimbursement. The CNS completed checks in 2025 of services delivered in 2022, while discussions with providers were still under way when the report was prepared.

The €21.8m was separate from the report’s headline €6.2m fraud and abuse figure. The CNS described the long-term care reviews as plausibility checks and did not classify every repayment as the result of deliberate fraud.

Since the checks began in 2018, long-term care providers have agreed to return €89m. The report did not say how much resulted from overbilling, inadequate evidence that staffing requirements were met or other failures to justify the services claimed.

Deficit confirmed at €102.1m

The annual report also confirmed that the health and maternity insurance scheme ended 2025 with a €102.1m deficit, compared with the €102.5m shortfall previously forecast. Revenue reached €4.78bn and expenditure €4.88bn, reducing the reserve to €833.8m.

The CNS expected another deficit in 2026 and warned that the reserve could fall below its legal minimum in 2027 unless the financial position improved. Healthcare spending in Luxembourg rose 7.2% last year, while slower employment growth limited the increase in contribution income.

Elsewhere, the report recorded a sharp expansion of the direct-payment system, continued delays in handling some insured people’s files and preparations for electronic sick notes. It also covered the growth of long-term care, plans to move more treatment out of hospitals and continuing revisions to the schedules used to set medical fees and reimbursements.

The report offered no breakthrough in the dispute with the Association of Doctors and Dentists (AMMD). The AMMD ended the existing agreement in October 2025, and the CNS said negotiations on a replacement began in December.

The fund said its work with doctors under the agreement had included efforts to control the volume, relevance and price of treatment, including the use of equally effective but less expensive alternatives.

Against that financial backdrop, the CNS said it planned to make greater use of its data to detect irregularities and act more quickly. Its fraud unit also worked with other Luxembourg social-security bodies, neighbouring countries and the European Healthcare Fraud and Corruption Network.