MONTPELIER — An official leading Vermont’s push toward a single-payer health care system is calling efforts to coordinate electronic medical record between providers “wicked hard.”

Anya Rader Wallack, chairwoman of the Green Mountain Care Board, briefed the House Appropriations Committee on Thursday on progress the board has been making to retool Vermont’s health care system.

She said staff at the board have been working hard with hospitals, physician groups and other providers toward a goal of making the various providers’ computer systems better able to communicate with one another. But she says the challenges are huge.

In one example, Rader Wallack said the two largest hospitals serving Vermont, Fletcher Allen Health Care in Burlington and Dartmouth-Hitchcock Medical Center in Lebanon, N.H., use the same systems but have customized them, making communication difficult.