Diagnosis Code Set
General Equivalence Mappings
2012 Version Documentation
Appendix A—File and Format Detail
ICD-9-CM to ICD-10-CM
General Equivalence Mapping (GEM)
FILE FORMAT
| FIELD | POSITION | LENGTH | VALUE |
| ICD-9-CM Code [source] | 1 – 5 | 5 | Left justified, blank filled No decimal |
| Filler | 6 | 1 | Blank |
| ICD-10-CM Code [target] | 7 – 13 | 7 | All seven characters used, no decimal |
| Filler | 14 | 1 | Blank |
| Approximate [FLAG] | 15 | 1 | 1 = Yes/On 0 = No/Off |
| No Map [FLAG] | 16 | 1 | 1 = Yes/On 0 = No/Off |
| Combination [FLAG] | 17 | 1 | 1 = Yes/On 0 = No/Off |
| Scenario | 18 | 1 | 0 – 9 |
| Choice list | 19 | 1 | 0 – 9 |
ICD-10-CM to ICD-9-CM
General Equivalence Mapping (GEM)
FILE FORMAT
| FIELD | POSITION | LENGTH | VALUE |
| ICD-10-CM Code [source] | 1 – 7 | 7 | Left justified, blank filled No decimal |
| Filler | 8 | 1 | Blank |
| ICD-9-CM Code [target] | 9 – 13 | 5 | All seven characters used, no decimal |
| Filler | 14 | 1 | Blank |
| Approximate [FLAG] | 15 | 1 | 1 = Yes/On 0 = No/Off |
| No Map [FLAG] | 16 | 1 | 1 = Yes/On 0 = No/Off |
| Combination [FLAG] | 17 | 1 | 1 = Yes/On 0 = No/Off |
| Scenario | 18 | 1 | 0 – 9 |
| Choice list | 19 | 1 | 0 – 9 |
