Accounting for a medical biology laboratory in 2026

The accounting of a medical biology laboratory (LBM) is unlike any other. Revenue is largely framed by negotiated tariffs, cash flows pass through the French health insurance system and complementary insurers, and the production tool combines heavy analysers, perishable reagents and highly qualified staff. All within an often complex legal structure: an SEL, sometimes backed by an SPFPL holding, frequently operating across several sites. For a biologist owner, the challenge is not to "do more volume": it is to steer a constrained margin, tight cash and permanent compliance. Here is how a chartered accountant reads this kind of file.

Direct answer. An LBM is steered on three specificities: the operating structure (SEL, sometimes SPFPL, capital held by biologists), the economic model under negotiated tariffs (NABM, B letter-key, VAT exemption on care acts) and the double pressure of COFRAC accreditation costs and third-party-payment collection delays. The firm's role: turn these constraints into a dashboard.

Medical biology tests are coded under the medical biology nomenclature (NABM) and valued through the B letter-key. Prices are negotiated: a laboratory does not freely set its tariffs and can barely use price to improve profitability. The accounting consequence is direct. Performance is won on costs (reagents, payroll, organisation) and on volumes, far more than on tariff. In other words, an LBM's margin lever is internal: it depends on purchasing control and technical productivity, not on a pricing policy.

As care acts, medical biology tests are in principle VAT-exempt. This exemption comes with a counterpart many owners underestimate: the input VAT paid on reagents, analysers and services is not recoverable as it would be in a standard taxable activity. The "VAT-inclusive" purchase cost therefore becomes a real cost. Concretely, every euro of reagent carries its full VAT into the margin, which reinforces the importance of close monitoring of the reagents line. It is a point an LBM's accounting must isolate from data entry onward, not discover at year-end.

Almost all of an LBM's revenue runs through third-party payment: the French health insurance system for the mandatory share, complementary insurers (mutuelles) for the complementary share. The laboratory produces the act today but collects later, and from multiple payers. This generates a large volume of receivables to track, rejections to reprocess and a structural working-capital requirement.

Monitoring the DSO (average collection period) on third-party-payment receivables is one of the most telling indicators in the file. A growing laboratory can post good results while straining its cash, for lack of close monitoring of receivables and rejections. It is the classic gap between production and collection, particularly treacherous under negotiated tariffs.

Since order no. 2010-49 of 13 January 2010 (the medical biology reform known as the "Ballereau order"), accreditation has been mandatory for all LBMs. It is provided for in article L. 6221-1 of the French Public Health Code, is based on the NF EN ISO 15189 standard and is granted by COFRAC (the French accreditation committee). Since 1 November 2021, a laboratory can no longer carry out tests on scope lines for which it is not accredited: in practice, accreditation covers 100% of the activity.

This is not a one-off formality but a recurring, multi-year cost: a quality function (quality manager), documentation and quality management system, internal and external audits, and fees to maintain accreditation. The accounting stake is twofold. First, identify these charges clearly rather than diluting them in undifferentiated overheads. Second, decide what is an expense for the period and what may, where relevant, be capitalised. Isolating the full cost of accreditation relative to revenue allows a decision on grouping or pooling to be made on facts rather than endured.

An LBM is most often operated as a professional practice company (SELARL or SELAS), a form suited to a regulated profession. Capital ownership follows rules specific to healthcare professions: the medical biologist is a physician or pharmacist biologist, and both capital and voting rights remain regulated.

Above the operating company, one frequently finds an SPFPL (financial holding company for liberal professions), which holds the shares of one or more SELs. This holding structure organises ownership among partners, finances an acquisition or external growth and structures the flow of profits upward. The sector is undergoing marked concentration (groupings, multi-site networks), which makes the quality of patrimonial and tax structuring decisive.

Beyond the tax return, an LBM is steered on a few ratios. Thresholds depend on the profile (single site, network, specialised) and are calibrated file by file.

To go further on these specificities, see our dedicated page: chartered accountant for medical testing laboratories.

A multi-site LBM operated as an SELAS was hesitating over closing or grouping a peripheral site seen as "just breaking even". Three angles were examined: the real margin per site (not the overall result), the full cost of accreditation allocated to each location, and the third-party-payment DSO, which was more degraded on the site concerned due to unprocessed rejections. The review showed the site was not structurally loss-making: it suffered from poorly steered collection and duplicated quality costs. The decision could be taken on figures, not on an impression. These elements are specific to the file and are not a transposable benchmark.

This work falls within our bookkeeping and accounting review engagement, with analytical tracking by site and by line.