All of the 18 prime providers for the Work Programme have passed the Merlin Standard, which sets out how they should treat voluntary and private sector subcontractors.
The assessment company emqc assessed the providers in each of the four main areas covered by the standard, including the design of their supply chains and their conduct.
It looked at such factors as how well they communicated with their subcontractors and how they honoured their financial obligations to them.
Eleven of the providers were deemed to have an achieved a "good" score of 70 per cent or more; the other seven were assessed as performing to a "satisfactory" level against the standard. None fell into the "excellent" category, which requires a score of 85 per cent or higher. A score of 54 per cent or lower would be deemed "unsatisfactory".
Rehab JobFit, a partnership between the Rehab Group, a charity based in Dublin, and the support services company Interserve, was assessed as satisfactory and given a score of 67 per cent.
All of the prime providers were required to gain Merlin accreditation in order to be a Department for Work and Pensions prime provider or risk losing their contract. The DWP is the only government department to have adopted the standard.