New Playwrights' Theatre recently met its 1985 fund-raising goal of $250,000 -- 10 months after its board of trustees announced it would close the theater permanently unless that sum was raised in 90 days.

The campaign was extended "because the response from the community was so extraordinary . . . we realized the main goal of expanding the theater's funding base would still be accomplished in the long run," said Daniel Kiernan, president of New Playwrights'. "We are not yet out of the woods," he added, "but a foundation has been laid for stabilization and growth."

More than $60,000 was raised from the Washington corporate community and more than $100,000 from foundations. Individuals contributed more than $73,000, $31,000 of which came from the theater's subscribers and audience members.

Arthur Bartow, New Playwrights' artistic director, said that during the course of the campaign "we paid off $40,000 in the most onerous debts that would have been fatal to the theater." New Playwrights' still has a deficit of $30,000 to $40,000, he said.

Having achieved its fund-raising goal, the theater announced the four plays that will complete its season, which resumes Jan. 8 with "Secret Honor." The play about Richard Nixon reunites the original team of actor Philip Baker Hall, director Robert Harders and designer Russell Pyle, who created the Los Angeles production and duplicated it for the Robert Altman film, which had a brief run in Washington last spring.

"Earth and Water," by Bethesda-born playwright J.R. Dalton, premieres Feb. 27. Bartow called the drama about the voyage of a group of boat people through the South China Sea "a tone poem" and "the most challenging play we will produce this season."

John Richardson's "Brotherhood," which simultaneously shows three brothers as they are now and as they will be in 12 years, opens April 3. The play, which was read last summer at the O'Neill playwrights' conference, will be directed by William Partlan.

Concluding the season will be "Something Blue," a sentimental and comic look at three women and the wedding ritual by first-time playwright Peg Sheldrick. Ronald Ross, New Playwrights' assistant artistic director, will direct the play, which opens May 8.

Also, Broadway musical veteran Barbara Cook and her musical director, composer Wally Harper, will perform a benefit concert for New Playwrights' on Jan. 24 at George Washington University's Marvin Theatre. For ticket information for both the plays and the benefit, call 232-1122. 'Jerry's Girls' Hits; 'Willows' Misses

"Wind in the Willows," the Kenneth Grahame children's-classic-turned-musical, originally staged at the Shakespeare Theatre at the Folger two years ago, closed Sunday in New York, two days after opening to unfavorable reviews.

Meanwhile, "Jerry's Girls" appears to have scored a 14-to-1 opening night Broadway victory -- receiving 14 "excellent notices," according to publicist Peter Cromerty (the one adverse notice coming from the powerful New York Times). The musical revue, which 16 months ago had a try-out at the Eisenhower, starring Carol Channing, Andrea McArdle and Leslie Uggams, has been significantly changed and now showcases Dorothy Loudon, Chita Rivera and Uggams. Coupons for 'La Cage'

The $10 discount coupons for tickets to "La Cage aux Folles" you may have seen around town were released by the National Theatre to help bolster sagging sales between Thanksgiving and Christmas, traditionally theater's slowest time of year. One batch of coupons was good through Dec. 15, with a second batch good through tomorrow's performance.

With maximum receipts of $400,000 per week, "La Cage" had been averaging $350,000, but that figure dropped to $280,000 after Thanksgiving, according to Alma Viator, director of public relations for the National. The discount policy was "working real well," she said. Meanwhile, two performances have been added -- one on Jan. 6 (that's right, a Monday) and a "Shopper's Special" matinee, with all tickets priced at $20 or $25, on Jan. 8. The musical closes Jan. 11. 'Forbidden Broadway' Discounts

Special ticket prices for senior citizens are now available for "Forbidden Broadway," the musical comedy revue now in its third month at the Shoreham Hotel's Marquee Lounge. Those 60 or older can see the show on Sundays for $10, with performances Tuesday through Friday priced at $15.50.