That is what I read too and it makes total sense and we like things done right and safe. Any ideas how to fix it without adding the 1/2 inch and making a huge mess of it?

Not really at this point.

Ok thank you for responding. i am windering if we can just clean up the concrete and stain it to match the flagstone for the time being and see how that looks.

I would try to make the concrete as level as possible + add some stain. If that doesn't work, then come back and we can try to think of other ideas (although, the only idea I have involves removing 1/2" of the bottom step).

A 1/2" is pretty noticeable. my daughter's top step (inside house) was off by less than 1/2" (maybe 3/8") - and the inspector didn't notice it when he did his inspection. However, my daughter tripped on it quite a few times during the first 1-2 months after they moved into their house.

they purchased the home while living in another state - houses were going so fast that they had to jump on one or lose out - not that this would have stopped them from purchasing it - but at least she would have known before moving in - she kept tripping and thought something was wrong with her balance. She is used to it now - but will need to fix it before they decide to sell in the next few years.

Personally I would have that bottom flag stone step cut out- removed and install a new one.

Half inch is HUGE in the steps world. 1/8 would be noticed and could be a tripping hazard. Standards are there for a reason. Do it properly--the hard way. Sorry.

In addition to what @millworkman said, if this is being inspected, make sure the rizer opening is less than 4".

This all makes sense. we will stain it and if that looks bad and doesnt work well we will cut it out. I will have to check the rizer measurements since i am not sure. its steel frame doesnt allow a lot of room to change if its not be we can fox the step if we need to. its perfect the way it is and none of us have tripped on it this way

If the height of the bottom step can take a wood plank I would attach one to it.

Yes, that would be ideal. The problem is it will change the step depth and trying to avoid a trip hazard. we will try to get it at as thin as possible but there will still be a variance

Is the current bottom step is equal to the others?. If it isn't then the installer messed up. Otherwise I would try your method and stain it to match.