Map of ZIP Code. ZIP code 90803 is centered in Los Angeles County and overlaps Medical Service Study Area(s) 78.2kkk and 78.2kkk. Census tract(s) 06037576602, 06037576700, 06037577200, 06037577300, 06037577400, 06037577501, 06037577502, 06037577601, 06037577602 and 06037577603 overlap this ZIP code area too.Other ZIP codes nearby.ap of ZIP Code. ZIP code 90803 is centered in Los Angeles County and overlaps Medical Service Study Area(s) 78.2kkk and 78.2kkk. Census tract(s) 06037576602, 06037576700, 06037577200, 06037577300, 06037577400, 06037577501, 06037577502, 06037577601, 06037577602 and 06037577603 overlap this ZIP code area too.