5 Replies Latest reply on May 22, 2020 1:56 AM by Lidio Rivera

    Is there a way to "Decode" a US Military service number from WWII?


      Is there a way to decode a US Military service number from WWII service.

      What can we find out by the military service number??  For example can we find out when they joined the military?


      For example  Francis X Lavallee  Serial number 20114562


      And what about Joseph W. R. Sevigny  6137273


      Both of these individuals died during the war.  So no military records available to find out their past.  For example Lavallee was in Artillery before he went for training to fly planes.  He died in a training accident.  So they, military,  have him assigned to the US Air Corp but no record of when he join the shore battery of Artillery here in Massachusetts.


      Any help/suggestions would be greatly appreciated.  thank you.



        • Re: Is there a way to "Decode" a US Military service number from WWII?

          Hi Stephen -


          What is probably going to be the best use to you is the Electronic Army Serial Number Merged File (Enlistment Records) which covers most enlistees from 1938-1946. It's searchable by serial number. It will give you the place of enlistment, the date of enlistment, their grade, branch, year of birth, civilian occupation, and component of the Army, among other information.


          Here is the link to search: NARA - AAD - Fielded Search - Electronic Army Serial Number Merged File, ca. 1938 - 1946 (Enlistment Records)


          Best of luck in your hunt!

          4 people found this helpful
          • Re: Is there a way to "Decode" a US Military service number from WWII?



            While the Army and Air Force records from 1912 to 1963 were effected by the St. Louis fire in 1973. We have been able to reconstruct some of the military service of Francis Lavallee. You may request this record by completing a Standard Form 180 and mailing it to:


            National Personnel Records Center

            1 Archives Dr.

            St. Louis, MO 63138


            A Standard Form 180 may be found at: Start Your Military Service Record (DD Form 214) Request


            Unfortunately, the record of Joseph Sivigny was completely destroyed in our fire. You may also request both of their Individual Deceased Personnel Files by writing to:




            ATTN: AHRC-PDC


            FORT KNOX, KY 40122-5405

            2 people found this helpful
            • Re: Is there a way to "Decode" a US Military service number from WWII?
              Stephen Carfora Adventurer

              Stephen B.


              I found three web pages (see below) that deal with the “decoding” of military service numbers from World War II.  According to these sources, the first two digits of the 8-digit serial number for Francis X. Lavallee indicate that he served with the National Guard in World War II.  I confirmed this when I found his record in NARA’s Electronic Army Serial Number Merged File (Enlistment Records).


              Things got more complicated when I tried to decipher the meaning of the remaining six digits. For instance, the third digit ("1") could mean that he went into the National Guard from one of the New England states ... or from Hawaii! I know, Hawaii was not a state yet, but see the Wikipedia entry below for more details. The remaining six digits may also give some clues as to when he joined the military but I did not drill down deeper to try to figure that out.


              I have summarized below how the three web pages address the National Guard connection for Lavallee's serial number.


              (1) “How to Decode a WWII US Army Serial Number,” by  Amy Johnson Crow:


              First digit = 2 = federalized National Guard service

              "When you have an 8-digit serial number, the second number shows the Service Command. This narrows down where the person enlisted or was drafted. If you have a serial number for a member of the WAC, look at the number after the letter prefix. There’s an exception. Remember those serial numbers that begin with “2,” showing National Guard service? You need to look at the 3rd digit. (The second digit for those will always be a zero. You knew there’d be some exception, didn’t you.)"

              Third digit = 1 = Connecticut Maine, Massachusetts, New Hampshire, Rhode Island, Vermont


              (2) “US Army WWII Dog Tags” by Alain Batens:


              “National Guard (1940) start with digits 20, followed by a third digit (indicating Corps Area/Service Cd)”


              (3) "Service number (United States Army)," by Wikipedia:


              “Beginning in 1940, National Guardsmen who were federalized were given Army service numbers in the 20 million range with numbers ranging from 20 000 000 to 20 999 999. Guardsmen federalized from Hawaii were issued service numbers beginning with 20 1 while 20 2 through 20 9 was used randomly by other states.”


              Stephen C.

              • Re: Is there a way to "Decode" a US Military service number from WWII?
                Lidio Rivera Wayfarer



                I'm sure you have already found the answers you were seeking but just in case you're still looking then the suggestion made by aabney2016 will yield some useful results on the 2 individuals you cited. Lavallee's info can be found by using the name and service number you listed. Sevigny's info is there as well but he is listed as Joseph W.P.R. Sevigny. Search either under his full name or just under the surname and then select him from the list.

                This doesn't tell how to decipher a service number it it should provide the basic facts you were seeking. Requesting the actual records, if available, as suggested by Therese Fitzgerald may provide more detailed answers.


                Good luck.