Thank you for reaching out to us.
It is halachically preferable to immerse without any foreign substance on the nails (including polish, gel, shellac, acrylic/gel nails, etc.), so women typically remove any polish prior to immersion.
However, since manicures are in place to beautify the nails, polish may not always be considered a chatzitzah, especially if it is long lasting like gel. A woman may be permitted to immerse with a gel manicure in some situations, as long as there are no gaps or chips (and her nails are cleaned well). To satisfy these conditions, a gel manicure may need to be filled prior to immersion.
There is a range of halachic opinion on this matter, so a woman who intends to immerse with gel may wish to check in with the mikveh in advance of immersion.
Learn more about the halachot of nails and mikveh immersion here.
Please be in touch with any further questions.
This response was updated on 15 January, 2024.