Psychiatrists at St. Elizabeths Hospital agree that John W. Hinckley Jr. is not ready to leave the hospital grounds by himself one day each month or to be transferred to a less restrictive ward at the institution, the government said in court papers filed yesterday.

Hinckley has been at St. Elizabeths since June 1982 after being found not guilty by reason of insanity of attempting to assassinate President Reagan in March 1981 outside the Washington Hilton.

Hinckley last month asked U.S. District Judge Barrington D. Parker, who presided at his trial, to ease his confinement.

The government submitted an affidavit by Dr. Joan A. Turkus, Hinckley's psychiatrist since 1982, in which she said that agreeing to Hinckley's request would not be "clinically appropriate at the present time." She said that although Hinckley's condition had improved since he was admitted to the hospital, "his mental illness is not totally in remission."

In a separate affidavit, Joseph Henneberry, director of the John Howard Pavilion, which houses patients who have been committed to St. Elizabeths after criminal proceedings, also opposed Hinckley's request. Henneberry said that if Hinckley were allowed to move unaccompanied about the city, "it is not possible to state that Mr. Hinckley would not present a danger to the community."

A hearing on Hinckley's motion is set for March 24.