Do the benefit limits imposed by the RIB-LIM create situations where the surviving spouse reaches the max widows benefit before FRA? I think the answer is yes although I have been told otherwise.
RIB-LIM is the term used by Social Security to describe the process used to calculate survivor benefits for widows and surviving divorced spouses who qualify for benefits based on the record of a worker who drew reduced Social Security retirement benefits prior to their death. And yes, if RIB-LIM applies it means that ae surviving spouse would become eligible for their maximum possible survivor rate at some point prior to reaching their full retirement age (FRA).
For example, say Bob starts drawing his Social Security benefits at age 62. Because he started drawing benefits prior to FRA, RIB-LIM would limit the survivor rate for any widow or surviving divorced spouse who qualifies for benefits on Bob's account to a maximum of the higher of a) Bob's reduced benefit rate or b) 82.5% of Bob's primary insurance amount (PIA). Assuming that Bob didn't suspend his benefits or lose benefits to the earnings test before he died, 82.5% of his PIA would be the higher of those 2 amounts. And, depending on her year of birth, Bob's surviving spouse would become eligible to start drawing the full 82.5% at some point roughly between ages 62 & 62 1/2. Bob's surviving spouse could choose to start drawing as early as age 60 instead, but in that case she could only be paid 71.5% of Bob's PIA (https://secure.ssa.gov/apps10/poms.nsf/lnx/0300615322).
Our software (https://maximizemysocialsecurity.com/purchase) is fully programmed to handle RIB-LIM computations, so widows and surviving divorced spouses should strongly consider using the software to determine their best strategy for claiming benefits.