The Internal Revenue Service claims that the Maryland-National Capital Park and Planning Commission owes $78,000 in back taxes for failing to make proper tax deductions from the salaries of those of its employees who live in Commission-owed houses and are who permitted take-home cars.

The commission has 90 planning employees who live in commission-owned houses in either Prince George's or Montgomery counties. Some are charged no rent because of their position with the commission, while others are paying only half of what would be charged if their houses were rented at their market values, according to John Hoover, commission spokesman for Montgomery County.

In addition, 40 employees of the bi-county are allowed to use commission cars going to and from work.

Edward Navarre, the commission's secretary-treasurer, said the IRS has "verbally" informed the planning agency that such iringe benefits for its employees are considered taxable income.

Navarro said the commission is awaiting a written report from the IRS on how much money is owed, but that "$78,000 is the figure they've mentioned . . . We are trying to negotiate that figure downward, but I don't think they will."

Richard Farlow, the IRS investigator assigned to the commission case, said he could not comment on the IRS ruling. David Estey, spokesman for the IRS in Baltimore, also refused to discuss the case.

For the past 20 years, the planning commission has offered some of its employees the chance to live in houses the agency obtains when it acquires parkland, according to Hoover.

He said those who live rent-free or get a 50 per cent discount on their rent are employees such as golf course caretakers and park superintendents who are required to live on park-owned property because of their jobs.

Other employees may apply for housing and are granted living quarters "on the basis of need," Hoover said. Some of these employees make up to $25,000 a year, according to Navarre.

Hoover said that in the next three years these employees will be required to pay at least 25 per cent of the market value rent for their homes.

Hoover contended that the rents the commission charges are proper because the commission does not provide the full services of a landlord. It pays only for furnace and roof repairs, he said, while the tenant is responsible for regular upkeep plus electrical and plumbing repairs.

Hoover said the commission also will argue that some employees should live rent-free since the location of their home is "a condition of their employment."

Navarre said that the 40 employees - including himself - who are permitted to take home commission cars are either on call 24 hours a day or are required to attend frequent night meetings. Navarre said that the IRS complaint is with 25 other employees who were using take-home cars before 1975 but have since had the privilege revoked. He said he is the only one of the 40 whose use of a take-home car is currently being questioned.

Navarre said he is not yet sure how the commission will pay the back taxes but that "it is my personal opinion that the commission will not seek reimbursement from the employees."

Royce Hanson, commission chairman could not be reached for comment.

According to IRS spokesman Estey, fringe benefits are taxable if they are granted for the benefit of the employee, rather than the employer.