WASHINGTON — The Education Department on Friday issued new guidelines for how school districts nationwide should comply with a recent Supreme Court ruling that allows public school teachers to offer remedial help to students attending parochial schools.

The department said that only public employees could offer the remedial help, which is federally funded through a program called Title I, and that their teaching assignments in parochial schools have to be made without regard to their religious affiliations.

Also, any classroom used to deliver the Title I instruction to parochial students must not contain religious symbols, the guidelines state. School districts can begin offering the new form of academic assistance to parochial students at any time.

The Supreme Court’s 5-4 decision on the issue overturned a ruling it made 12 years ago forbidding public employees to teach inside parochial schools through the Title I program, on the grounds that doing so violated the separation of church and state. This time, a court majority said that having federally funded instruction inside parochial schools could be constitutional as long as there are safeguards.

The ban had forced state and local school districts since 1985 to fulfill the requirements of Title I by sending public teachers to instruct parochial students at alternative sites, usually a van parked outside religious schools.

But federal education officials called that a poor learning environment for students who need remedial help in subjects such as math or reading and said it was wasting millions of dollars that could be spent on more direct academic aid.

More than 190,000 parochial schoolchildren nationwide receive publicly funded remedial instruction through Title I, at a cost of about $40 million a year. Much of it has been spent on the costs of teaching children at an alternative site.

The guidelines also state that all materials and equipment used to help parochial students through Title I cannot be used for other instruction, that public teachers cannot team up with private school teachers to instruct students and that public teachers cannot participate in religious activities at the school.