Thanks for your response. I know of many "employers" who offer and pay for retiree medical and I have never seen it reported on any sort of tax document. This is why I thought a 1099-NEC did not appear correct. However you point about what the employee signs as part of their retirement benefits should be a great start for my client to discuss. 

If the employer is not willing to adjust the 1099-NEC in 2024 but indicates they will correct moving forward can a work around be to record the Medicare Premium B expenses on a sch C to offset the income? I know this is not an ideal situation but a way to document receipt of the 1099-NEC so not to ignore. With a 1099-R you can recategorize the income as non taxable, but with a 1099-NEC there is really no way to identify it as non-taxable. 

Hopefully the employer will remedy the situation. 

Thanks again for your feedback!