A locum, or locum tenens, is a person who temporarily fulfills the duties of another; the term is especially used for a physician or clergyman. For example, a locum tenens physician is a physician who works in the place of the regular physician when that physician is absent, or when a hospital or practice is short-staffed. These professionals are still governed by their respective regulatory bodies, despite the transient or freelance nature of their positions.
Locum tenens is a Latin phrase meaning "place holder", akin to the French lieutenant. The abbreviated form "locum" is common in Australia, Canada, Ireland, Malaysia, Singapore, New Zealand, South Africa, and the United Kingdom; unlike in Latin its plural is locums. In the United States, the full length "locum tenens" (plural: locum tenentes) is preferred, though for some particular roles, alternative expressions (e.g., "substitute teacher") may be more commonly used.
In the United Kingdom, the NHS on average has 3,500 locum doctors working in hospitals on any given day, with another 17,000 locum general practitioners. Many of these locum hospital doctors are supplied by private agencies through a national framework agreement that the NHS holds with fifty-one private agencies. NHS figures show that approximately eighty percent of hospital locum positions are filled by agencies on this framework. The remaining twenty percent are filled by agencies working outside this agreement. Locum agencies are common reference points for doctors wishing to work in this market. According to a report published by Royal College of Surgeons, the NHS spent approximately £467 million on locum doctors through agencies in the year 2010.
On the other hand, GP locums (freelance general practitioners) mostly work independently from locum agencies either as self-employed or via freelance GP chambers based on the NASGP's Sessional GP Support Team (SGPST) model. Some GPs have been employed by the primary care trusts (PCTs) to provide locum cover. However, PCTs were abolished in 2013 and replaced by the clinical commissioning groups (CCGs). CCGs are now starting to employ salaried GPs with locum roles. Locum GPs are expected to be flexible, adaptable, resourceful, professional, quick to establish relationships, familiar with different IT systems, and able to independently manage risks.
Locums provide a ready means for organizations to fill positions that are either temporarily vacant or for which no longterm funding is available. Working as a locum allows a professional to gain experience in a variety of work environments or specialties.
However, the locum situation also poses a number of disadvantages: the transient nature of the assignment means extra stress and work for locums whenever they assume a new position, and for the hiring organisation, this generally means that the required flexibility and lack of guaranteed income must be rewarded with higher compensation. These may in the long term create higher costs for the hiring organisation than adding more full-time positions, especially in highly skilled professions, and unlike the situation in some professions where cheap temporary labour or significant use of interns actually undercuts wages and reduces total staff costs.
In professions that require knowledge of patient histories, locums may provide work of lower quality or be perceived as doing so. They may experience resentment from permanent staff because they are paid more or considered to shoulder less responsibility.