Originally Posted by junkcollector
As long as the 2 disconnects and 100 amp panel are closely grouped and operating as service equipment now, (as a legal installation) there is no reason why they cannot be fed from the one meter. It would be best to install a splice cabinet / terminal box below the meter box to split up and feed the three panels instead of triple lugging the lugs in the meter. (Illegal in most cases)
All disconnects must be within reach of each other. Two are currently in the basement with the third undefined but it suggests it is on the main floor since it was not defined as in the basement like the other two. As well, since this was 3 apartments, chances are the 2 panels are not next to each other.
ALthough they may have one now, the last time I looked for a 200 amp meter that would accept multiple lugs, there was no such animal.
The other option OP has is to use panel as main and the other 2 as subs to that main. Since all the feeds were right out there at the meters, I figured that would be easier to do.