Sage MAS 90 and MAS 200 version 3.71 and higher are presently supported by Sage. This means that in most instances you can obtain the current release levels, service updates (if any) as well as tax table updates.
There are some restrictions on what older versions of MAS 90 and MAS 200 are entitled to.
For example, versions 4.20 and earlier no longer receive service updates. Instead if you find an error you’ll have to beg and plead ask for an individual program fix. Also, version 4.05 and lower no longer have the knowledgebase kept up to date – so if you’re looking for a problem report on a version 4.0 issue you’ll probably not have much luck.
Curious what the restrictions are on the supported levels of Sage MAS 90, MAS 200 (and MAS 500 is even thrown in for good luck)?
Here’s the PDF showing all versions starting with 4.30 and their appropriate level of support.