The organisations said in January that they were considering a merger and announced yesterday that it had been completed.
The Nomad Trust will operate as part of Lincolnshire YMCA but the names and branding used individually by the two charities will be retained.
Lincolnshire YMCA had an income of £2.3m in 2011/12; the Nomad Trust’s income was £570,000. The merged organisation will have a budget of about £3.1m for 2013/14.
Malcolm Barham, chief executive of Lincolnshire YMCA, said neither charity had lost any staff in the process of merging. The organisation now employs 150 staff, made up of 130 from Lincolnshire YMCA and 20 from the Nomad Trust.
Barham said the organisation was in the process of reviewing the services offered by the combined charity, but added: "It doesn’t mean cutting services out, but it might mean reshaping. We are talking to partners locally about how we can give them the best service and avoid duplication."
He said that the merger had gone well overall but added "once we get working as one organisation, that might change for some people".