Please see the answer below.
Box 12 codes
are:
- A -- Uncollected Social Security or RRTA tax on tips
- B -- Uncollected Medicare tax on tips
- M -- Uncollected Social Security or RRTA tax on taxable
cost of group-term life insurance over $50,000 (former employees only)
- N -- Uncollected Medicare tax on taxable cost of
group-term life insurance over $50,000 (former employees only)
https://ttlc.intuit.com/replies/5343209
