A new tax incentive program for employers coupled with an improving economy has brightened the outlook on summer employment for Washington-area youth this year. But teen-agers still face a tough job market, officials in most jurisdictions here say.

Thanks largely to an expansion of the 1977 Targeted Jobs Tax Credit (TJTC) measure, approved last year by Congress, most area government and job placement officials report that young people are having better success in finding summer jobs this year than last.

The new TJTC provision, under which employers can receive an 85 percent credit for the first $3,000 paid to low-income 16- and 17-year-olds, has enabled many companies to expand their work forces at an ultimate cost of only pennies per hour, corporate spokesmen said.

"For the price of a cup of coffee an hour, you can hire a kid this summer," said Fred Kleisner, general manager of the Capital Hilton, whose hotel has hired 16 teen-agers to spend the summer rearranging the storeroom. "The youngsters will be getting $3.50 an hour, and we'll pay 50 cents an hour in the end."

"We think TJTC is a plenty good incentive," said Jack Hamlin, vice president of Peoples Drug Stores. Peoples will add at least two teen-age employes at each of its 35 District stores through TJTC. The teens will earn the minimum clerical wage of $3.50 an hour in D.C., or $3.35 for an initial three-month training period.

The drug chain will hire more salespeople and cashiers this summer than last at its 130 metropolitan stores, Hamlin said.

"Last year there was just a ton of negative economic news, but I'm a lot more optimistic now," said Henry Bernstein, business development representative for Montgomery County's Office of Economic Development.

"It's a bit better than last summer, and the response from the private sector has improved," said Anne Bland, coordinator for Alexandria's Youth Employment Program.

Firms that have hired or plan to hire youth here this summer include Burger King, McDonald's, Hechinger, Woodward & Lothrop, Giant Food, Safeway and the Marriott Corp., according to area employment offices.

The Hilton's Kleisner, vice chairman of the Greater Washington Board of Trade's human development program, is helping with its 1983 Summer Jobs for Youth Campaign, chaired this year by former Redskins halfback Larry Brown. Working with the chambers of commerce in the region, the board has set up and is advertising a job placement telephone service that matches youths who want to work with employers who want to hire them.

The number to call is 296-JOBS.

The Board of Trade's efforts are considered supplementary to job placement programs already operated by local, state and federal offices. Last year, the board and chambers identified about 12,000 jobs in the private sector while the District of Columbia's federally subsidized summer jobs program provided another 20,000. In addition, the federal government has its own student hiring program, which last year placed more than 37,000 young people, including about 5,600 in this area.

Officials say the Washington area needs to improve its summer hiring since the region has an overall unemployment rate of more than 18 percent among 16- to 19-year-olds in the job market. In the District, nearly 37 percent of that age group is unemployed, and among black city youths, unemployment is almost 43 percent, the most recent data shows.

Hechinger plans to hire about 200 summer workers and is still taking applications for its 17 stores. TJTC is "a real good incentive. And we feel we have gotten good quality people," a spokeswoman said. "Our intent is not just to offer summer jobs, but to hopefully get them to come back and develop it into a career."

McDonald's has hired a substantial number of teen-agers for the summer as part of its nationwide goal to add 30,000 jobs by July 1--an average of 20 new workers for each of the 1,500 company-owned stores, said a spokesman at its Illinois headquarters. Summer is the busiest season for the 6,000-store fast-food chain, and McDonald's has asked that the 4,500 franchise-owned stores also consider new hiring under TJTC programs.

Burger King, with about 40 franchises in the region, plans to have 800 to 1,000 part-time jobs this summer, slightly up from last year because of increased sales, a spokesman said. One drawback to the TJTC program, a spokesman said, is that managers want to hire people quickly to cope with rapid turnover. Yet those they hire must first be certified as eligible for the program, which often means extra paperwork that chain restaurants say they "are not administratively oriented" to handle.

Not everyone expects summer hiring to increase this year, even with the interest in the tax credit program.

"I don't see any appreciable difference--we tend to call businesses more than businesses call us," said Robert Reade, executive vice president of the Arlington Chamber of Commerce.

While Prince George's County and Alexandria report that the tax credit program has helped their job placement efforts, Fairfax and Montgomery counties say they are having trouble filling requests for low-income workers.

Richard James, a summer employment coordinator for the Virginia Employment Commission's main Northern Virginia office, said affluent areas don't have many youths poor enough to qualify for the tax credit program.

A youngster in a family of four is eligible for TJTC if the family income is $10,770 or less. "A family that makes $15,000 to $17,000 may be considered too well off, but those families aren't having it easy either," James said. He said the eligibility standards should be reviewed.

James also said that many high school students who don't have the skills to land better paying jobs are apt to shun lower paying positions, especially if their parents earn good incomes.

"Some can be very picky when their parents are making $150,000 a year," he said. "They are turned off by any kind of fast-food places or minimum wage work."

Jobs are available in fast-food, lawn care, delivery and some offices. The Northern Virginia VEC office, for example, is filling an employment request for 100 youths to help deliver directories.

The crush of student job-hunters is expected to swell in the next week or so as high schools and the few colleges still holding classes recess for the summer. Some counselors already are feeling the onslaught of youngsters who let their search for employment go until the last minute.

Just this week at Wakefield High School in Arlington one student dropped off a note at job counselor Jane Vandell's office with only this panicky message: "Help, help--I need a job."