IC fixtures are required to be marked as such and the IC does not have to be in the model number, it could be a separate marking. The requirement for this marking goes back to the 1987 NEC (as far as I can tell). If your house was built a year or two before this, I don't think any can would be IC rated.

There is a requirement for a thermal protector in a recessed can that goes back at least as far as the 1987 code. The thermal protector is not an indication that the can is IC rated.

Air tight cans would not have any slots.

You should be able to find the manufacturers name in the fixture and with luck, a catalog number. Using that information, you can visit their web site & get more information. My feeling is that if you don't see the IC marking, the fixture is not meant to be in contact with insulation.

If you cannot find the IC marking permanently on the fixture it is NOT IC rated.
ALL IC cans are permanently marked, most commonly by stamping into the metal.

Thanks guys. I managed to get in the attic and saw the can from a distance. Insulation was very neatly fanned out away from it. I still can not find a model number. The house was built in 1987---right on the fringe of the rule changes. I think I have to assume its NOT IC rated. So, I really need to get it replaced when it warms up.

In the interim, I have seen recessed lights w/out the eyeball but with a lens over them--like in my closet. I wonder if I could replace the ball with the lens until I get a new can? That should help with the draft. My only concern would be mositure from the warm room hitting one side of the lens vs the cold air on the other side. What do you think? Its either that or removing the bulb and fashioning some sort of cover for the winter...doubt the wife would like the looks of that!

There are trims available that are air tight independent of the housing. Both Halo and Juno have these that fit some older fixtures.

I will look. Do you know if these have exposed bulbs or rather lenses that the bulb sets behind. I have a can with a lens in my closet. This might stop the draft downstairs at least until I get the can changed. I would just be a little concerned that the warm side of the room and the cold side might create moisture on the lens....?

I found two types of Halo air tight trims that say IC/Non IC so I assume they are safe to use. They are metal so I hope no moisture developes. Hopefully they fit. One is a simple non-eye ball spot light. The other has a small glass bulb and was designed for the shower but may look better. Either way I have to remove the socket from the piece that moves up and down in the can and drop/snap it thru the opening in the trim. I hope these things were standard and they fit my 20 year old recessed can!

THANKS!!!!!

Problem Solved. I used a regular round trim that came with a lens....the kind you see in a closet. In fact I took the trim out of our closet! I popped a 75 EF bulb in. Its not very bright but casts a nice amount of light in the fireplace area and seems to block the cold. I had another option too...in fact I used it in the closet. It was a IC / Non IC shower trim kit. It is an airtight kit that comes with a samll glass bulb...sort of a mini mushroom. I had to bend the metal rods that pop into to the can that 'push up'. It was not a perfect match I guess. Also the socket for the bulb in my can does not come apart so I simply lowered it to the opening in the new kit. I believe it should all be safe and now I have a lot of light in the closet; again I used a 75W EF bulb.

BTW, the closet can said not to insulate around it so I assume the can downstairs is the same.