Old leaves not well suited to your new light conditions, compared with where it came from.

Keep feeding it, water it moderately, and it should soon start to put out new leaves better suited to your light.

How often are you watering? It looks as though it is growing outdoor.

Assume you do have sun in Boston (in the summer), so don't think it's sun related.

Thank you so much for your comments and help!!

I water once or twice a week, depends on how humid the soil is. I use fertilizer spikes, I guess they're not too good. Thanks again for your help!

There is no exact answer when one is trying to figure out yellow leaves..

If there is a Nitrogen problem, then ones needs to get to the root of the problem which can be caused by many reason..

One thing I have figured out after all these years is there is never a concrete answer for any situation. Some factors are a bad soil choice, over watering, lack of light, over heated roots, cold roots, extreme temps, the wrong fertilizer, past root damage that can all lead to deficiencies...I would do the process of elimnation, and figure out the root cause one factor at a time..

This you do by giving us as much detail as possible..Let's start with the kind of mix it's in? It looks like cedar chips or red wood which would rob nitrogen from your soil as soon as it starts to decompose, which to me it looks like that.

In the last picture, it almost looks to dry, which can cause leaaf wilt and severe root damge right away...Causing roots to not function properly once watered which leads to root rot and then nutrient and water uptake almost impossible..

Or it could be porr fertilizing habits or using a fertilizer that does not meet the needs of your tree.

As John says, a huge change in sunlight can also drop the leaves that were use to Califorina light and temps, which is nothing close to us here in Boston.

My first guess though is the mix, since 80% of the time is always the culprit to begin with..

The soil is a mix between regular potting mix and topsoil in a rate 2-1.

I don't think I have overwatered it doing it pretty much once a week. The tree gets a lot of light during the entire day even though it's not direct. The leaves started turning yellow four days ago so I'm guessing it's going to be a lack of nitrogen.

Im gonna try a new fertilizer with more nitrogen and I'll let you know

I live in Florida. My Meyers are growing in full sun in sand. I spray Citrus Nutrient Spray every two months. Florida has a citrus disease affects the roots. It is State wide. It is recommended to spray with the Citrus spray to get nutrients into the tree if the roots are not healthy.

My thought is your tree suffered some root damage and you could try using a spray fertilizer to see if your tree greens up which might carry it though the period of making new roots. It is inexpensive and you have nothing to lose.

I have been taught that wood chips should never be placed around citrus in the ground. I don't know if that would be the same with a potted plant. Florida soil is pure sand, like beach sand. You should never mulch with anything around a citrus tree when planted in the ground.

Since mine are grown in the ground, I don't know if the same would apply to a potted plant.

Citrus spray

I will add that i have a small orange tree in a container and some of the leaves were turning yellow. It turns out that i had white flies under the foliage.

I removed the wood chips and tried the new fertilizer. I'll let you know how it goes.

I also thought about bugs, but I have inspected every leave and didnt find anything.

Thanks for all the suggestions!