PORTLAND — The company under fire for its poor performance as a provider of non-emergency transportation for people in Maine’s Medicaid program failed to obtain a performance bond as required by its contract with the state.

MaineCare patients have lodged thousands of complaints against Coordinated Transportation Solutions of Connecticut, mostly from people who say they have missed medical appointments or been left stranded.

The Maine Department of Health and Human Services has threatened to cancel the company’s $28.3 million contract.

State officials said the company’s performance bond could be revoked.

A performance bond would help cover the state’s cost to transition to a new broker if it canceled Coordinated Transportation Solutions’ contract

But an agency spokesman told the Portland Press Herald (http://bit.ly/IhQK5i ) there is no performance bond.

A company official refused comment.