Three District of Columbia medical schools have decided to bow to a U.S. order to accept a quota of American students now in foreign medical schools, even though the students might not meet the three schools' standards.

The decision to accept 564 such students has been made by 109 American medical schools so they can continue to qualify for $84 million in federal aid that they claim they cannot afford to forego.

The local schools at Georgetown, George Washington and Howard universities - receive about $2 million a year of such aid. "The funds are necessary for us to operate," Dr. Marion Mann, Howard medical dean, said yesterday.

But 14 schools, with Johns Hopkins in Baltimore a leader, have told the Department of Health, Education and Welfare they will sacrifice $7 million in aid rather than have the government dictate whom they can admit.

The medical students to be admitted nationwide are some of the more than 3,000 who have enrolled in schools mainly in Mexico and Europe because they could not gain admission to schools in the United States.

Federal health officials announced that Georgetown, George Washington and Howard must admit a total of 25 such students next fall - to assume federal "capitation" aid of $1,000 to $1,500 for each student.

The issue still is being fought in Congress, with officials of the American schools seeking at least greater control over composition of their student bodies and, they maintain, the quality of doctors they graduate.

The issue started when medical schools in recent years found themselves besieged with applicants. Some foreign schools then began admitting large numbers of frustrated Americans and charging them high tuition.

Many of those students are well-to-do, and they and their parents formed a powerful lobby to try to force their admission by American schools.

In a measure pushed hard by Rep. Paul Rogers (D-Fla.) and Sen. Harrison A. Williams (D-N.J.), Congress voted in 1976 to require schools receiving capitation aid to accept a state group of Americans at the end of their second year abroad if they could pass a National Board of Medical Examiners test. The schools are required to do so in the fall of 1978, 1979 and 1980.

American medical educators argued that their standards include more factors than passing tests and that they might have to accept some students who could never make up for two years for what there educators deem inferior training received in some foreign schools.

"We're against the principle that usurps" a school's right to decide who will enter, said Dr. Richard Ross, John Hopkins' medical dean, in announcing his school's intention to pass up capitation aid.

Rep. Rogers and others have argued that the nation needs doctors and that Americans abroad eventually will become doctors here anyway and should be given a better education.

Amid a flurry of attempts to change the 1976 law, the House and Senate have yet to compromise on the issue.

Under the admissions plan, Georgetown must take 10 students. Howard must take nine and George Washington only six because it has admitted voluntarily several such transfer students.

Even though Howard must have the capitation aid, according to Dean Mann, "the $1,050 a student we get will still be pitifully small" because Howard now spends $14,000 a year to train each student.

Freshman medical students currently are charged $12,500 a year in tuition at Georgetown and $9,000 annually at George Washington. These charges are two of the highest in the country.

"Every dollar we didn't get (in federal aid) "would force us to push tuution up more," said Dr. Ronald Kaufman, GW's medical vice president.