ClearAll[Cusip]
rules = Thread[(ToString /@ Range[0, 9]) -> Range[0, 9]]~Join~
   Thread[CharacterRange["A", "Z"] -> Range[26] + 9]~Join~
   Thread[Characters["*@#"] -> {36, 37, 38}];
Cusip[cusip_String] := Module[{s = cusip, sum = 0, c, value, check},
  If[StringLength[s] != 9,
   Print["Cusip must be 9 characters!"];
   False
   ,
   s = Characters[ToUpperCase[s]];
   Do[
    c = s[[i]];
    value = c /. rules;
    If[EvenQ[i], value *= 2];
    sum += Floor[value/10] + Mod[value, 10];
    ,
    {i, 8}
    ];
   check = Mod[(10 - Mod[sum, 10]), 10];
   s[[-1]] === ToString[check]
   ]
  ]
Cusip /@ {"037833100", "17275R102", "38259P508", "594918104", "68389X106", "68389X105"}