Rather than using a series of substrs you could populate the four variables in one fell swoop using unpack.

use strict;
use warnings;

use Data::Dumper;

my %zipDB = ();

while ( <DATA> )
{
    chomp;
    my ($zip, $state, $areaCode, $city)
       = unpack q{A5 A2 A3 A*}, $_;
    $zipDB{$zip}
       = join q{|}, $state, $areaCode, $city;
}

print Data::Dumper->Dumpxs([\%zipDB], [qw{*zipDB}]);

__END__
00601PR787ADJUNTAS
00602PR787AGUADA
00603PR787AGUADILLA
00604PR787AGUADILLA
00605PR787AGUADILLA
00606PR787MARICAO
00610PR787ANASCO
00611PR787ANGELES
00612PR787ARECIBO
00613PR787ARECIBO
[download]

Here's the output

%zipDB = (
           '00611' => 'PR|787|ANGELES',
           '00612' => 'PR|787|ARECIBO',
           '00603' => 'PR|787|AGUADILLA',
           '00610' => 'PR|787|ANASCO',
           '00606' => 'PR|787|MARICAO',
           '00601' => 'PR|787|ADJUNTAS',
           '00602' => 'PR|787|AGUADA',
           '00605' => 'PR|787|AGUADILLA',
           '00613' => 'PR|787|ARECIBO',
           '00604' => 'PR|787|AGUADILLA'
         );
[download]

Cheers,

JohnGG