Question on Different "Zones" for Rome Transportation Pass

I wonder if what's confusing you is that those passes do NOT include travel from the Fiumicino airport into Rome. They should, however, include the town of Fiumicino, which is where you'll be staying. You might want to check this site out as well: http://www.roninrome.com/%20transportation/how-do-i-get-to-fco

Are you talking about the weekly CIRS pass, or the monthly Mensile a Zone? This is when being able to speak/read a little Italian helps. The Italian language section of ATAC makes it clear that you can buy those passes for as many zones as you want. http://www.atac.roma.it/index.asp?p=14 shows what I mean. But beware - you purchase a "Mensile a Zone" pass for a calendar month ("mese solare"). If you aren't going to be in Ostia precisely from the 1st to the last day of the month, you'll probably want to buy a series of CIRS passes. The CIRS is purchased for any 7 day period at a time, and you control when it gets activated. (Ron In Rome can probably confirm/correct this, if he's reading.) But my question is, if you're just one block away from the single zone, why do you feel you need to buy a two-zone pass? Can't you just walk the block to be inside the single zone? Am I missing something? I hope that info is helpful.

Thanks fou your help! I am going to take a look at that site now. Your question is a good one and the answer to your question is this: we thought of that same thing, walking to the boundary. However, we went to google.com/maps and did a street view and did a virtual "walk" to where the boundary is. At first it is pedestrian friendly, but once you hit the river, the sidewalk on the bridge is very narrow. After you cross the bridge, there are't any busstops for another "block" or so, and it's very woodsy and there is nowhere for someone to walk. It's a main road and doesn't look very safe. But yes we are on the same page as you in the respect.

Also now that I look at the map, it's about 3 streets up. Not that it matters because that part of the walk is fine, it's crossing the bridge and after that isn't.
Take a look: Via Monte Vies, 00054 Fiumicino, RM, Italia is the address on google maps, do the street view and "walk", make a right on Via della Scafa and follow that until it meets with Via di Tor Boacciana. Cross the bridge and that's when it starts getting iff-y.

So looking at the website, I see that the majority of Rome is in Zone A. And the Fiumicino area I am speaking of is in Zone B. Now, for the Mensile a Zone pass, 1 zone is 21 EURO and 2 zones is 30 EURO, which tells me that Zone A and B (2 zones) would both be covered by the 30 EURO pass. However, 30 EURO is the cost of the monthly pass anyway that doesn't include Fiumicino. So would I need a 3 zone pass for 51 EURO? Or is this completely different from the "normal" monthly pass and therefore has its own rates and levels?

Thanks Michael! No I am ok understanding that part. FCO is like its own city with a city so to speak so none of the passes apply. Fiumicino is consider Zone B, but I was able to take that website you gave me from ATAC and stick it in Babel Fish and decipher an answer to my question. The monthly pass I need is 51 EURO although it's a "3 zone" pass. Apparently Rome city center and Rome Commune are counted as 2 zones for that pass, making Fiumicino and other areas directly outside the boundary a 3rd zone. Also, the bus A3002 run by Cotrl can be caught along that route and take us to Ostia where we can do whatever we want from there. Whew!