Chief executive David Hurcomb said that the firm had recognised a £2.2m exceptional loss for irrecoverable contract costs.
NG Bailey had been working for Carillion on the stalled Midlands Metropolitan Hospital project.
It was managing the design and installation of the full MEP installation worth £80m, when project work was halted half-way through in January.
In latest private accounts for the year to March 2018, NG Bailey also took £2.1m of exceptional restructuring costs, mainly for the IT Services division.
Despite this, Bailey posted pre-tax profit up 6% to nearly £20m on revenue marginally down at £481m.
The dip in turnover was put down to current economic challenges and a small number of cancelled projects.
Since the year-end NG Bailey acquired facilities and power engineering specialist Freedon Group.
The additional of the 600-strong team lifts overall headcount to 3,000 staff.