Thirteen persons were indicted by a federal grand jury here yesterday on charges of making false claims for D C unemployment compensation totaling $31,500.

Assistant U S Attorney Charles Roistacher of the grand jury division said the persons made the claims while they were employed at full-time jobs in the Washington area.

Roistacher said the indictments bring to 83 the number of persons charged in a continuing investigation into unemployment compensation fraud here. He said that the 13 charges yesterday, however, are the first to be filed in federal court under a statute that carries a five-year maximum jail term. The others were charged in D C Superior Court under a three-year maximum penalty statute.

Attorney Robert Hallock of the Unemployment Compensation Board said the approximately 70 D C Superior Court cases had involved about $130,000 in illegally obtained unemployment payments. Sixteen of those persons have been sentenced to jail terms of up to three months.

Named in yesterday's federal indictments are:

James E Diggs, 31, 1300 Southview Dr., Oxon Hill, 35 counts involving $4,600 in allegedly falsely obtained payments; Robert L Ussery, 40, of 3 K Ter NW, $2,200 in 11 counts; Howard D Smith, 45, of 3222 8th St SE, 18 counts involving $2,500; Nathaniel Robinson, 33, of 8534 10th St NW, 17 counts involving $2,850; Oscar Philips, 46, of 35 U St NE, Seven counts involving $1,650; Willie Parkerr Jr., 30 of 5510 Clay PI NE, 10 counts involving $1,300.