Remodeling a kitchen. I'll be adding two new circuits dedicated to the microwave and fridge. I'll also be reconfiguring the countertops which will result in having to add another outlet to meet code for power distribution.
Haven't done any major wiring changes for a while and I'm now seeing that AFCI is required basically anywhere in a dwelling outside the bathroom. The two new circuits I'm adding will require AFCI breakers so I'm now planning to purchase those.
Since I am adding an outlet down the line to an existing series of countertop receptacles, am I required to also update this circuit to AFCI? I'm not having any luck finding an NEC reference that states this is a requirement, but I also can't find anything that dictates what might be grandfathered in certain circumstances. However, I also know that typically any changes require bringing whatever is being changed up to code so I feel like this is probably the obvious answer to the question.
How about lighting? If I add another light to a circuit serving only luminaires, do I also update that to AFCI?
The existing outlets are already GFCI protected so the only concern is adding AFCI here. Obviously, AFCI is better and I do understand the purposes of the protection it offers but the cost of upgrading half my panel due to a bunch of little changes would not be small.
Edit: I'm located in MI. I couldn't find anything in the MI IRC but I could have missed something.