A chain of fixed-term contracts (Kettenbefristung) occurs when an academic employer links one fixed-term contract to the next. Whether that is lawful depends mainly on the total duration, the reason for the fixed term and the type of post. If you work in academia, it helps to know the limits before the next contract is due.
Kurz beantwortet: A fixed term needs a material reason, or it may run without one for no more than two years (section 14 TzBfG). For academic staff, the Fixed-Term Contracts in Academia Act (WissZeitVG) caps qualification-related fixed terms at six years before a doctorate and six years after it, and at nine years after a doctorate in medicine (version last amended on 25 May 2020). Whether a chain is lawful in a given case is decided by the labour court if there is a dispute.
The most important points at a glance
- A fixed term without a material reason is limited to two years under section 14(2) TzBfG, and up to three extensions are possible within that period.
- For academic staff, the WissZeitVG requires that the fixed term serves your own academic qualification.
- Before a doctorate the maximum is six years; after a doctorate it is also six years, or nine years in medicine.
- The total duration counts, not the individual contract. A series of short contracts can therefore reach the limit.
- In a dispute, the labour court decides on the individual case.
What does a chain of fixed-term contracts mean legally?
The term describes a succession of fixed-term employment contracts with the same employer. The Part-Time and Fixed-Term Employment Act requires a reason for every fixed term. A material reason exists under section 14(1) sentence 1 TzBfG where the fixed term is justified, and the list in section 14(1) sentence 2 gives examples such as a temporary need for the work or a fixed term following a course of study (section 14 TzBfG).
For academia, the WissZeitVG is the more specific standard. It applies to contracts with academic and artistic staff, with the exception of university professors (section 1(1) sentence 1 WissZeitVG). A fixed term is permitted there where it serves your own academic qualification (section 2(1) WissZeitVG).
How long may a qualification-related fixed term last?
The maximum depends on whether you already hold a doctorate. The table summarises the basic rules of the WissZeitVG and the TzBfG as they appear in the statute.
| Situation | Maximum duration of the fixed term | Legal basis |
|---|---|---|
| Before the doctorate | up to six years | section 2(1) sentence 1 WissZeitVG |
| After the doctorate | up to six years | section 2(1) sentence 2 WissZeitVG |
| After the doctorate, medicine | up to nine years | section 2(1) sentence 2 WissZeitVG |
| Fixed term without a reason under the TzBfG | up to two years, extendable up to three times | section 14(2) TzBfG |
The statute looks at the qualification period as a whole, not at a single contract. The figures come from the statutory text in the version last amended on 25 May 2020 (gesetze-im-internet.de).
When does a chain become a problem?
A chain becomes critical mainly when the total duration reaches the legal limit, or when a stated reason appears to be a pretext. Limits therefore lie not only in the number of years, but also in the course of the contracts and their purpose.
Typical situations are third-party funded posts, covering posts and qualification posts that follow one another. Each case needs its own review. The labour court examines the contract, the job description and the purpose of the fixed term.
A worked example of total duration
Total duration can be checked with a simple calculation. Assumption: you have not yet completed a doctorate and have already worked on fixed terms for four years in qualification posts. Up to the six-year maximum before the doctorate, two years remain. A further contract of three years would exceed that limit unless an exception applies. Whether earlier periods count in a particular case depends on the individual facts and how the contracts were drafted.
The same logic applies after the doctorate, with other figures. The maximum is then six years, or nine years in medicine. If you apply for a post after your doctorate, keep track early of the time already used.
Signs of a problematic chain
Indicators for a closer review often show up in the pattern of the contracts. They include uninterrupted follow-on contracts with the same employer, tasks that remain unchanged for years and a reason that is repeated word for word in each contract. Such patterns do not prove that a fixed term is unlawful, but they show where a question is worth asking.
- Uninterrupted follow-on contracts with the same employer over several years
- Tasks that stay the same despite new contracts
- A stated reason that repeats word for word in every contract
- A post that is refilled straight away when it ends, without any change in purpose
Which role do third-party funds and reform plans play?
Third-party funded posts are treated differently under section 2(2) WissZeitVG. The fixed term can then follow the project period if the funding has been approved for a specific task and period. If you move from one third-party post to the next, pay close attention to the funding purpose.
The reform of the WissZeitVG is under discussion. A draft bill is not current law, and which changes will finally be adopted is open. The German articles on the amendment for assistants and on the postdoc fixed term after the reform (in German) put the plans into context.
Frequently asked questions
Can my employer no longer fix my contract once six years are reached?
Under the WissZeitVG, a qualification-related fixed term is capped at the maximum durations described above. A further fixed term then needs a different reason or must be dropped entirely. Whether a new reason exists depends on the individual case.
What happens once the maximum duration is reached?
A further fixed term then needs its own reason that does not rest on qualification alone. In practice, this often means that a post with a different purpose is created, such as a teaching role or a project post with clearly defined tasks. Whether that succeeds depends on the case. Anyone in this position should have the contract checked before signing.
Do student assistant contracts count towards the maximum?
That depends on the type of post. Student assistants do not automatically fall under the qualification rule of the WissZeitVG, because that law targets academic staff. Ask the university on which legal basis your post is fixed-term.
What is a re-employment bar?
The question is whether an employer may fix a new term after a previous fixed-term contract. The German article on the re-employment bar in the WissZeitVG (in German) explains what applies afterwards.
Can I challenge a fixed term?
Yes, but only within the statutory time limit, so act early. A challenge to the fixed term must be brought in time. Seek advice early, for example from a trade union, a legal adviser or the works council of the university.
What to do next
- List all earlier fixed-term contracts with start date, end date and stated reason.
- Calculate the total duration against the maximums under the WissZeitVG and the TzBfG.
- Ask the personnel department on what legal basis the next fixed term rests, and request a written answer.
- If in doubt, have the position checked by a trade union or a legal adviser before you sign a new contract.
Related articles
- Academic careers: contracts, collective agreements and fixed terms
- What is the WissZeitVG? Fixed terms in academia explained (in German)
- WissZeitVG amendment: what the draft bill plans for assistants
- Postdoc fixed terms: what the reform plans after the doctorate (in German)
- Re-employment bar in the WissZeitVG (in German)
Sources: WissZeitVG (gesetze-im-internet.de, last amended 25 May 2020), TzBfG, section 14 (gesetze-im-internet.de, last amended 20 July 2022), University of Hamburg, information for student employees (last updated 29 June 2026).
Last updated: November 2026. This guide is general information, not individual advice.
