Reply to 490
Here is definition from IRS Instructions for code 1G:
Offer of coverage to employee who was not a full-time employee for any month of the calendar year (which may include one or more months in which the individual was not an employee) and who enrolled in self-insured coverage for one or more months of the calendar year.
Because your example was a FT employee for at least 1 month during 2015, I would not think the code 1G would apply.
I think having code 2C on line 16 for all 12 months (since they were covered all 12 months) would be correct.
NOTE: I am not an expert on the codes, so please don't 'quote me'.
How are you getting this person generated on one form? Do you use the same PERNR for both the employee and retiree record?