ICD-9-CM/ICD-10-AM First Edition to ICD-10-AM Twelfth Edition

Purpose:
Provides the link between two editions of the classification.
Backward maps provides equivalent code for new codes in the newer edition.
Forward maps provides equivalent codes for deleted codes in the newer edition.
The maps provide an equivalent code that best matches the concept from a clinical perspective (called historical maps) as well as an AR-DRG perspective (called DRG maps previously logical maps). Sometimes the historical map and the DRG map are the same code.
Multiple historical maps are provided where there are multiple codes that can be mapped from one edition to the next. The first historical map provided in the mapping table is the closest match to code descriptor, alphabetic index entries or relevant coding conventions.
To map between multiple editions, users need to use all the mapping tables between these editions. For example, to map between Tenth Edition and Twelfth Edition, users need to use the mapping tables for both Eleventh Edition and Twelfth Edition. Codes need to be mapped from Tenth Edition to Eleventh Edition, then from Eleventh Edition to Twelfth Edition.

Use Case & Benefit:
Interpretation of coded data using codes from various editions of the classification for data tracking and trend analysis.

Licensing Required: Yes from Fifth Edition onwards (prior to Fifth Edition available on IHACPA website) 
Frequency of Maintenance: Mapping tables released with each new edition
Source: ICD-9-CM/ICD-10-AM (First Edition to Twelfth Edition) 
Destination: ICD-10-AM (First Edition to Twelfth Edition)
Map Direction: Bidirectional, one to one and one to many