Once you retire, are you able to add an award to your DD 214 if you receive your retirement award late??

Yes. You have to file a DD215 to have your 214 amended.

Yes but you need verification

I got out in Nov 1975 with 10 1/2 years service. Was told by 1SGT that I had been recommended for the Meritorious Service Medal. Never received it or heard anything about it until 2006 when I wrote the MilPerCen for a list of awards I was entitled to. Number one on the list was the MSM with and award date 29Dec75. Took me 31 years to learn of the award. And the interesting part was I have made a similar request about 5 years earlier and the award did not show up. Included with the packet was a copy of the orders awarding the medal, but no certificate. In 2014 I again contacted them for a copy of all my military records and lo and behold, there was a copy of the award certificate. Not the original, but a barely legible xerox copy. I received a DD-215 showing the award.

Yes, you can!! But you would have to do a correction to military records. Just google correction to military records. It will take a few to complete on their end.

Yes. In the DD215

I've got the same problem. I retired in 1979 ( Sept 1) and a few weeks later got an MSM Certificate (dated Sept 12) and the Medal. Can't find the orders. I've written DA, etc., and alls I get was "I guess you were never awarded the Medal." I wrote back and asked if I was never awarded the medal how did I get the Certificate and Medal. Same answer. I don't wear my Medals on my PJs but would like it on my grave stone if and when I go. Any ideas???

There is a time limit for you to submit for a DD 215, a correction/ amendment to your DD 214. However, you can also submit a DD 149 to correct your military records.

Your situation is not terribly uncommon, but I think that it is a crime that units can't figure out how to do retirement awards in a timely manner. It isn't like a retirement sneaks up on you with all of the mandatory appointments and out processing stuff you have to do.

I hope this helps too.
https://www.rallypoint.com/answers/how-to-correct-your-dd214-and-other-military-records

Yes, and a DD215 will be issued.

Yes it can. As previously stated by SPC Matthew R, file a DD 215 and have copies of supporting documentation on hand.