Life insurance imputed income is the cost of offering someone life insurance coverage beyond $50,000 whenever there is a benefit provided by an employer to and employee.
E.g. if you're employer group life plan offers you $500,000 of term life insurance, than the cost of that insurance for $450,000 will be recognized by you as the covered insured as imputed income. It's income that is reported to the IRS and income on which you must pay income taxes.
Imputed income in life insurance is the dollar value of group life insurance that you either pay for at group rates, or get for free from your employer, that is above $50,000. Because you are getting it at a reduced cost, it is considered by the IRS to be of more value that you paid, and as such, is a taxable income per their schedule.
E.g. if you're employer group life plan offers you $500,000 of term life insurance, than the cost of that insurance for $450,000 will be recognized by you as the covered insured as imputed income. It's income that is reported to the IRS and income on which you must pay income taxes.