@Aminy
it appears that 414H contributions are exempt from federal tax, but subject to New York State tax. The amount should have been excluded from your box one taxable wages. If you look at your federal return, I don’t think you will see an add back. But they may be taxable in New York State, even if your wages are not taxable under the convenience of the employer rule.
https://www.osc.state.ny.us/retirement/publications/1530/contributing-toward-your-retirement
