As a locum you work outside employment under the NVZ and FMS model agreement, if you work exactly as it describes. You temporarily replace a named specialist who is absent, for a maximum of six months with one six-month extension. You do only medical work and you are free to work elsewhere.
NVZ is the Dutch Hospital Association. FMS is the Federation of Medical Specialists. A model agreement is a template contract that the tax authority has assessed in advance for payroll tax.
In short
- The tax authority assessed the MSB locum model agreement on 1 March 2023 (no. 905-2023-19163-1-0). There is also a version with the hospital as the principal (no. 905-2023-19163-2-0).
- Locum work is temporary only: a maximum of six months per absent specialist, with one six-month extension. Structural locum work is not covered.
- Existing model agreements may be used until 31 December 2029. The certainty only applies if you actually work as set out in the agreement.
In this article
What does the NVZ and FMS locum model agreement cover?
The model agreement covers temporary locum work for a medical specialist whose work cannot be absorbed within their own specialty group. There are two versions: one with the MSB as principal and one with the hospital as principal. The tax authority assessed them on 1 March 2023 (Belastingdienst, assessment 905-2023-19163-1-0).
If you work under the agreement, the principal does not have to withhold or pay payroll taxes. The tax authority does make a reservation. For care in a hospital it is "very difficult" to rule out an employment relationship in advance on the basis of an agreement. That is why the conditions are strict (assessment, explanatory note point 1).
The assessment covers payroll taxes only. Whether you are an entrepreneur for income tax or VAT is assessed separately by the tax authority (assessment, point 3). If you work through your own company, the assessment says nothing about corporate income tax.
How long may you work as a locum under this agreement?
The assignment lasts no longer than the absence of the specialist you replace, and in any case no longer than six months. If the absence lasts longer, a follow-up assignment of no more than six months may be given once (model agreement, NVZ and FMS explanatory note).
Structural locum work must not be the starting point. An MSB is not meant to keep signing new agreements with the same locum for the same specialty group. If different specialists in one group drop out one after another, the same locum may replace them in turn, with the time limit applying per replaced specialist (NVZ and FMS explanatory note).
What do you do, and not do, as a locum?
You do medical work only. Other tasks belong to the permanent members of the group: no management tasks, no training of specialist registrars, no working groups or regular research and no meetings of the medical staff or the MSB. You are also not part of the medical staff (NVZ and FMS explanatory note, points 4 and 5).
You run risks that an employee does not. When absent, including through illness, you are not paid. You are not entitled to paid leave. You are liable for damage caused in carrying out the work. And you arrange your own disability or pension provision if you think you need one (explanatory note, point 6).
During and after the assignment you are free to work elsewhere, including within the hospital's catchment area, without the principal's permission (explanatory note, point 8).
Locum work is not necessarily worse for patients. A US study of over 1.8 million hospital admissions found no difference in 30-day mortality between patients of temporary and permanent internists. Costs were higher, however, and patients stayed in hospital 0.43 days longer on average (Blumenthal et al., 2017). That is an association in the United States, not proof for the Netherlands.
If your work does not fit these arrangements, for example because you provide structural extra capacity, NVZ and FMS advise an employment contract based on the Terms of Employment for Medical Specialists (AMS) (NVZ and FMS explanatory note).
What must the MSB check when it hires you?
If the MSB hires you to work in the hospital, this is intermediation. The MSB is then the principal, and you work for a third party. For this there is a deemed employment relationship: a situation where the law requires payroll tax even without an employment contract (assessment, point 2).
That deemed employment does not apply if it is plausible to the MSB that you work as an independent entrepreneur. The tax authority mentions, among other things: you have several clients, you are BIG registered and registered with the Chamber of Commerce, you are responsible and liable for the care yourself, you are free to work elsewhere and you contribute to the liability insurance (assessment, point 2).
If you work for only one MSB for more than six months, that certainty lapses. According to the tax authority, anyone too dependent on one MSB lacks economic independence (assessment, point 2). If you work as a self-employed professional through your own company, also watch the Wtza: according to the CIBG, a company providing medical specialist care needs a licence (Toetreding zorgaanbieders, self-employed (in Dutch)).
Do you charge VAT on your locum fee?
You do not charge VAT on the rate for the care, if you meet the conditions of the medical exemption. The tax authority expressly lists the medical service performed while covering for a colleague as exempt (Belastingdienst, Examples of exempt medical services (in Dutch)).
Insurance costs are different. The principal passes on to you a proportionate share of the liability insurance premium. VAT is due on that recharge. The principal therefore invoices it separately, and the costs may not be included in your locum fee (NVZ and FMS explanatory note, point 7).
For the share of the premium that relates to the specialists, the tax authority accepts a national estimate of about 60%. That may differ considerably from the actual situation in your hospital (explanatory note, footnote 6).
How long can you still use the model agreement?
Until 31 December 2029. Since 6 September 2024 the tax authority no longer assesses new model agreements. Approved agreements that were valid on that date may still be used until 31 December 2029, even if the agreement states a different validity (Belastingdienst, No more new model agreements (in Dutch)). The assessment itself gave a validity of five years from 1 March 2023.
Since 1 January 2025 the tax authority has been enforcing under the normal rules again. It can impose correction obligations and additional assessments, and since 1 January 2026 also penalties for gross negligence or intent (Belastingdienst, Enforcement (in Dutch)). A model agreement only helps if you work as described. In case of doubt, the court looks at all circumstances together, as the Supreme Court set out in 2023 (Supreme Court, 24 March 2023, ECLI:NL:HR:2023:443). More on this in the DBA Act and false self-employment.
From 31 December 2026 there is a legal presumption of an employment contract at an hourly rate below € 38 (Ondernemersplein, Low hourly rate of a self-employed person may lead to an employment contract (in Dutch)). A legal presumption means the principal has to prove that there is no employment contract. For locum specialists this only matters at a rate below that limit.
The care sector is asking for room for self-employed professionals. In a letter to the House of Representatives of 12 December 2025, LHV, FMS, KNMT, VvAA and InEen wrote that covering peaks and sickness with self-employed professionals is unavoidable in medical specialist care. They asked for risk-based enforcement in 2026 (Letter from care organisations to the Standing Committee on Social Affairs, 12 December 2025). That is the sector's position, not a rule.
Sources
- Belastingdienst, Sector model agreement for locum work in the MSB for medical specialists, NVZ and FMS, assessment no. 905-2023-19163-1-0, 1 March 2023, with NVZ and FMS explanatory note (in Dutch). download.belastingdienst.nl
- Belastingdienst, No more new model agreements (in Dutch), accessed 1 November 2026. belastingdienst.nl
- Belastingdienst, Employment relationships and enforcement by the tax authority (in Dutch), accessed 1 November 2026. belastingdienst.nl
- Belastingdienst, Examples of exempt medical services (in Dutch), accessed 1 November 2026. belastingdienst.nl
- Supreme Court of the Netherlands 24 March 2023, ECLI:NL:HR:2023:443. uitspraken.rechtspraak.nl
- Ondernemersplein (RVO), Low hourly rate of a self-employed person may lead to an employment contract (in Dutch), accessed 1 November 2026. ondernemersplein.overheid.nl
- CIBG, Healthcare provider admission, self-employed (in Dutch), accessed 1 November 2026. toetredingzorgaanbieders.nl
- LHV, FMS, KNMT, VvAA and InEen, Committee debate on self-employment 18 December 2025: focus on risk-based enforcement, letter of 12 December 2025 (in Dutch). lhv.nl
- Blumenthal, D. M., Olenski, A. R., Tsugawa, Y. & Jena, A. B. (2017). Association between treatment by locum tenens internal medicine physicians and 30-day mortality among hospitalized Medicare beneficiaries. JAMA, 318(21), 2119. doi.org