[11] Mitie made its first acquisition in the health and social care sector in October 2012, when it spent £111 million on the homecare firm Enara.

[12] In April 2013, Mitie's chief executive, Ruby McGregor-Smith, was made non-executive director to the board of the Department for Culture, Media and Sport.

[15][16][17] In February 2014, Mitie announced an eight-year contract with the Home Office, making it the largest provider of immigration removal centres in the United Kingdom.

[18][19] Almost two years later, Mitie came under fire for its management of the immigration centres after the prison inspectorate stated that the facilities were "dirty", "rundown" and "insanitary".

[27] In November 2014, Mitie acknowledged that its homecare business was less profitable than had been anticipated and that it was struggling to recruit and retain sufficient numbers of care workers.

[31][32] McGregor-Smith announced in November 2016 that the company was withdrawing from the healthcare business (providing home care for the elderly) in response to spending cuts and rising employment costs that had made the sector unviable.

[35][36] During December 2017, following a string of three profit warnings in the space of four months,[37][38] McGregor-Smith stepped down from her role with the outsourcing group; she was replaced by former managing director of British Gas and current Chief Executive Phil Bentley.

[39] In June 2020, Mitie announced it was to buy Interserve's 40,000-strong facilities management business in a cash and shares deal worth £271m, later revised downwards to £190m.

[46][47] In 2024, Mitie also resisted paying a COVID-related bonus to its private nursing staff that public NHS employees were given, although it relented in the fact of industrial action.

[57] In February 2022, The Sunday Mirror revealed a Mitie WhatsApp group relating to immigration management paid by the Home Office that exchanged racist and offensive messages amongst colleagues since March 2020.