Q. What is the Age 55 Exception to the 10% penalty? 

A. The age 55 exception only applies to distributions made from qualified employee rertirement (e.g. 401k or 403b) or annuity plans – it does not apply to IRAs.
Distributions made to you after you separated from service with your employer, if the separation occurred after you reached age 55, are not subject to the 10% penalty tax.  

For the definition of age 55, IRC Notice 87-13 states… “such separation from service occurred during or after the calendar year in which the employee attained age 55.”