A Washington lawyer pleaded guilty in U.S. District Court yesterday to three counts of filing false and inflated bills with insurance companies that used those estimates as a basis for monetary settlements in automobile accident cases.

The attorney, Floyd W. Anderson, 43, of 2710 Daniel Rd., Chevy Chase, faces one year in jail and a $1,000 fine for his guilty plea to three false pretense charges in connection with $1,775 in inflated bills that were submitted to two insurance companies in 1977 and 1978.

Assistant U.S. Attorney Charles J. Harkins Jr. said in court yesterday that Anderson had the cooperation of a doctor and a dentist who prepared exaggerated treatment reports that Anderson submitted to the insurance companies.

Once a settlement agreement was reached with the insuror, Anderson would get a third of the proceeds, the doctors' bills would be paid and the client would get the remainder, Harkins told Judge Charles R. Richey during a court hearing yesterday.

The dentist involved, Dr. Clyde Narine, has pleaded guilty in federal court to one count of mail fraud and would have testified as a government witness if the case against Anderson had gone to trial, Harkins said. The physician, Dr. Marshall D. Nickerson, has been convicted in federal court of criminal charges in connection with a similar scheme, Harkins said.

Harkins told Richey yesterday that in one case in June 1978, the government's evidence would have shown that Narine's bill showed that he had pulled a tooth for one patient, prepared a false tooth and put it in place, when, in fact, Narine had simply capped a chipped tooth. According to Harkins, Anderson submitted a $675 bill to an insuror for that work, which was actually worth $200.

In another case in May 1977, Harkins told Richey, Anderson submitted a $450 bill to Geico insurance for seven office visits by a client to Narine, and for extensive dental work, when in fact there had been only one visit at a cost of $20. In the third case, Harkins said, Anderson in August 1978, filed a $650 bill, again with Geico, for 25 visits by a client to Nickerson. Harkins said, however, that the client would testify in court that she had seen Nickerson only four times.

In exchange for Anderson's guilty plea, Harkins said that the government would dismiss all other charges involving inflated insurance claims that were included in a 32-count grand jury indictment brought against Anderson last October.

Richey has not scheduled a sentencing date.