Officials at the The Mayor’s Fund to Advance NYC are scrambling to come up with an extra $4 million after federal officials pulled the plug on an anticipated grant for a mental-health program already underway.

The Connections to Care program, which trains social-service workers to identify signs of mental illness and provide non-medical mental-health services or referrals, was launched as a $30 million public-private partnership in March 2016.

While $10 million was anticipated from the feds, the program was defunded after just $6 million had been allocated for its first three years.

The Mayor’s Fund, a City-Hall affiliated nonprofit that has raised between $21 million and $25 million annually in each of the last three years, now needs to make up that difference.

“We are currently exploring sources for public and private funding to make up the federal funding gap, which does not go into effect until Spring 2019,” said Fund spokeswoman Cynthia Olson.

“Connections to Care is not being reduced or delayed,” she said.

She noted that 1,200 nonprofit staffers had been trained under the mental-health initiative, and that they had collectively served more than 15,500 participants over two years.

Connections to Care is also a key component of Chirlane McCray’s $850 million mental-health initiative, ThriveNYC.