If you own an apartment and leave it vacant for 6 months while you are out of the US are you required to pay the maintenance charges for utilities and security?

If you pay rent, you are renting and these charges go with the rent. This question arises every so often in NYC Condos/Co-ops, (which are owned as you state), where the charges are amazingly steep. The answer is the same in any case...they are not occupancy or use based charges...they are actually the responsibility of the "property" and will be paid by it (eventually by the Condo/complex foreclosing and selling the property to do so) and hence are really your responsibility as owner (or tennant), and in fact the property received the benefit of security and maintenance, even if your not there.