No flashing is really only effective when installed prior to the siding. Now it would probably only divert more water into the system.

I agree with millworkman. You need the stucco to be able to drain. Caulking the transition will do more harm than good.

Thank you guys for the quick response. Is my best bet to leave be at this point?

@charles ross would you mind giving some info on why the caulk would be a bad idea? Seems like the caulk would block some of the water that might seep in from storms.

Whether your stucco is true masonry stucco or EIFS, any water which gets behind it should be stopped from entering the wall by a weather-resistive barrier (e.g., asphalt-saturated felt, housewrap, etc.) That moisture should drain down the weather-resistive barrier via gravity to the bottom of the stucco. It needs a way out. Typically, there would be flashing installed so any water behind the stucco would be directed out on top of the stone cap and not behind the stone which is where it will go in your case. Here's a link to a video showing how it should have been done:

https://www.youtube.com/watch?v=01EXqOUsqxM

The weep detail at the bottom of the stone wall is now even more important. It would be interesting to see if the architect or designer provided any details for the stucco/stone transition or the bottom of the stone cladding. Absent those details, the default would be the manufacturer's instructions.

Well, it's happened again. Charles and I agree.

@Joseph Corlett, LLC,

Maybe we should play the lottery, Joe.