I'm interested in replicating research that was conducted with an earlier version of an ICPSR study. Is it possible to get those data?

Yes, ICPSR can supply an earlier release version of a study unless that version is unavailable for confidentiality reasons or at the request of the principal investigator. Please send your request to ICPSR-help@umich.edu and include the ICPSR study title, study number, principal investigator, and the date and/or version of the data of interest. Data will be supplied on cdrom, generally within a week or two of receipt of request.

How does ICPSR manage versioning?