The “Secret” Codes on Death Certificates That Can Tell You How Your Ancestors Died

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The “Secret” Codes on Death Certificates That Can Tell You How Your Ancestors Died

Finding death certificates for our ancestors is a critically important part of family history research. These important records contain information about when and where our ancestor lived and died and often include names of a spouse, parents, witnesses and, of course, a cause of death.

But the causes of death on death certificates are notoriously hard to read. Certainly, the more we research the better we get at deciphering the meaning of these sloppily written medical texts, but, very often, we are still left scratching our heads. Luckily there is a “secret” code on many of these documents that can help you make sense of this information and more fully understand how your ancestor passed.

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Let’s review a 1920 North Carolina death certificate for a man by the name of Daniel Adams. This document, like so many, is difficult to read due to the less than clear handwriting of the person who completed it.

In fact, the index for this record on Ancestry lists the first name as Savill, apparently due to the inability of the transcriber to read the document, which is what we originally also listed here. Thanks to the keen eyes of our commenters this possible error was pointed out to us and after some more research we confirmed that the name should, in fact, be Daniel. We have corrected his name throughout the article and additionally submitted a correction to Ancestry. It is a good lesson in how easy it is to misread a handwritten record, even when you have been doing so for decades – and how often indexes and transcriptions contain incorrect information, which can mislead us if we are not very cautious. 


The cause of death is particularly hard to decipher. But take a look at the number that is circled underneath this information. You have no doubt noticed codes such as this on death certificates in your own records.

This often overlooked number comes from the International Classification of Diseases (ICD), or the International Statistical Classification of Diseases and Related Health Problems as it is now known in full – and is currently maintained and updated by the World Health Organization.

The ICD was originally developed in the late 1800s and was known as the Bertillon Classification of Causes of Death, after its developer Jacques Bertillon, and later the International List of Causes of Death. The coding system was designed, in part, to provide a unified way to communicate and track causes of death and was used by a variety of nations. The US began using it in about 1898.

For this reason many official US death certificates after this time include these codes, as do certificates from many other countries at various times. The value to researchers today is that when causes of death are unreadable or confusing on a certificate we can look up the code and find the cause of death in a clearly written database. The information is made freely available online by Wolfbane Cybernetic.

To find the list of codes visit this page and then choose the revision that encompasses the year of your certificate. Because updates were/are made to the database about every 10 years you will need to access the correct revision. Information can change dramatically from revision to revision, so making sure you have the correct one is very important.

Since we want to investigate the code in the death certificate for Daniel Adams above, which was created in 1920, we will need to see which revision was created before this certificate was recorded. Revision 3 was created in 1920, but information from the CDC on the history of the coding system tells us that this revision wasn’t released until Oct of that year – so we will use Revision 2 (1909) since Daniel’s death happened in July 1920.

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Upon visiting the page for the 1909 Revision we search for code 126 and find that it corresponds to “Diseases of the prostate,” which is very helpful in understanding how this person died.

The number often relates to the contributory cause of death, if one is included. In the example below, this person died from myocarditis, damage to the heart, but code 131 corresponds to “Chronic nephritis.” Upon close examination we can see that, in fact, the contributing cause of death was a form of nephritis.

ICD Related to Contributory Cause of Death

Unfortunately, many death records do not contain this information. Numerous records that researchers have access to are not official certificates of death, were compiled by various religious or military organizations, are collections of information from other sources, or are simply indexes of the certificates themselves and do not contain detailed medical information. It is important to try and gain access to the original death certificate to gather this information.

However, even many official certificates do not make these codes available – and others may contain numbers that are not ICD codes at all. Be careful not to be confused by these. Oftentimes, ICD codes appear directly under or next to the cause of death and are sometimes circled or marked in some other way. Other codes found in this area, or in other locations on the document, many be codes for other information or from another coding system. The best way to know whether a number is an ICD code is to do your best to decipher the cause of death (and any contributing causes) yourself and then look up the code in the database to see if it seems a likely match.

The more recent a death certificate, the more likely that it will contain an ICD code. Often, these codes will appear as a two or three digit number, and on later documents they will often appear with a letter after them or even another number, such as 31a or 11a(2).

Now that you are armed with this information, why not pull out the death certificates you have already collected and check them for these codes? You might find that you are able to decipher a previously unreadable cause of death or gain more insight into those you have already figured out.

And if you’re on the lookout for no-cost death certificates online, check out our articles 50 Free Genealogy Sites and Free Genealogy Sites for Every US State for help finding them.

By Melanie Mayo, Family History Daily Editor

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Leave a response
  • Tracey Smith
    October 15, 2017 at 6:46 pm

    This still doesn’t tell you what the list of numbered codes are so you can refer to the list and look up the number.
    I’m looking for translation of Death Index cause of death number 2 from year 1955 New York, USA.

    • Sondra Clarke
      December 10, 2017 at 5:35 pm

      Tracey – Look up International Classification of Diseases on pinterest. #2 is “smallpox – not vaccinated”. I have it saved on my sight. Sondra Clarke

      • Sondra Clarke
        December 10, 2017 at 7:09 pm

        Update: In 1955 death caused for #2 is TB. Causes of death did change through the years. You need to know year of death first and then check the International Classification of Diseases to get the right COD.

  • Gail Burns
    September 4, 2017 at 4:10 pm

    Hello Annabelle I would be interested in reading above me tinned book on healing. Would you give me the name of it?

  • William Lewis
    August 10, 2017 at 7:49 am

    The cause of death was not as important as the witness of death and more importantly who signed the death certificate was more important. The funeral home that processed the arrangements was important. -Nothing Follows-

  • Isabel Flynn
    August 9, 2017 at 11:12 pm

    I wonder if the word at the end next to the 126 is Haemolysis ?

  • Dawn Cyr
    May 17, 2017 at 5:13 pm

    I am not sure how the laws are in other states, however in Maine, one can not get access to vital records unless it is immediate family. Unless the record is 100 years old. I was looking for my brother’s death certificate he died as a child, and would have been about 90 the Town Office told me I would have to prove we had the same mother. are there no laws like that on this site.

    • May 29, 2017 at 2:47 pm

      Hi Dawn,

      There are many states that lock vital records down so that they are almost impossible to access. Unfortunately, this comes from people not understanding how identity theft really works. To this end, I would suggest doing contacting your representative for your state government and asking them to consider sponsoring a “Genealogical Freedom Bill” which allows the state to create an informational form that can be distributed to the general public, but isn’t valid for identification purposes where employees of the vital records division can copy information from the original forms and send the non-identification form to the individual who is requesting the information. (If you need the record immediately, I would suggest going through Vital Check).

  • Annabell Romero
    May 15, 2017 at 4:13 pm

    I wrote a book about healing your family through you Ancestors. This will be so helpful because they will finally be able to start healing. My Grandkids are starting to take care of themselves with the food they eat. What vitamins are in their food. They had grandparents’ die of stomach cancer on both sides of their family.

  • K Ayers
    May 12, 2017 at 11:27 am

    My grandfather was stationed at Camp Daraga Mililitary Base in the Philippines in 1909. His wife died there in November 1909 but was reinterred and sent to San Francisco then on to San Diego for burial in January 1910. How can I find her death certificate?

    • K. Brueschke
      October 24, 2017 at 10:35 pm

      Well if your Grandmother died while she and your Grandfather were stationed in the Philippines, you can petition St. Louis for your Grandfather’s records. Because your Grandmother died while her husband was on Active Duty, there would, or should I say there should, be a Death Certificate for your Grandmother in his active duty file. Another place you can try is the National Archives in the Philippines, but I have no idea what or if they have any military records from that time period, who knows maybe you might get lucky and they have your Grandfather’s and Grandmother’s medical records all together. Another place you can look, and if I am wrong someone please correct me. But when someone is buried here in the U.S., who died somewhere outside of the county where the person is finally laid to rest, they are required to have a death certificate on file with the county registrar in order to bury someone in the county, correct? Might be a good place to try. But I will warn you now, that dealing with St. Louis, can be a lesson in utter frustration, I know it took me almost a year to get my medical records. Well I thank you for your Grandfather’s service and the next time you visit his grave, please leave a penny on the headstone for me. Have a good day!

    • Sondra Clarke
      December 10, 2017 at 6:46 pm

      I live in San Diego. Do you know where she is buried, i.e. Cemetery, private or military? I would be willing to try and get info. Also I have an Ancestry account and could try that also. Let me know what I can do 🙂

  • Cc
    May 12, 2017 at 6:22 am

    I was a coder for many yeats and advice is correct. Another thing to remember is that terminology changed thru out the years. Such as Apoplexy for srtroke and consumption for TB are two I can think of. the codling system was radically changed in 2014 .

  • Cc
    May 12, 2017 at 6:19 am

    I was a coder for many yeats and advice is correct. Another thing to remember is that terminology changed thru out the years. Such as Apoplexy for srtroke and consumption for TB are two I can think of. Also them codiing system was radically changed in 2014 .

  • Cc
    May 12, 2017 at 6:17 am

    I was a coder for many yeats and advice is correct. Another thing to remember is that terminology changed thru out the years. Such as Aoplexy for srtroke and consumption for TB are two I can think of. Also them coding system was radically changed in 2014 .

  • Valerie Makkai
    May 12, 2017 at 5:35 am

    Could the word after “prior” be “thrombosis”?

    • Anne Halford
      May 12, 2017 at 7:01 pm

      Before I read, the code I had predicted that it would say, “Prostrate Complicating. Peritonitis with poresis, Thrombosis

      • Marcia
        February 14, 2018 at 1:59 pm

        To me the first word is prostatitis complicated by
        peritonitis with paresis
        (maybe Thrombosis but I’m not sure–I don’t think it is tuberculosis myself)

        Enlarged prostate gland is contributing factor.

        Probably close enough for medical history use. (I did medical records and coding for several years.)

  • May 11, 2017 at 11:51 pm

    I found this to be true on some of my Canadian death certificates also. Thanks Melanie!

  • Robin
    May 11, 2017 at 8:16 pm

    Great information! I can’t wait to try it out!

  • Joan Lottner
    May 11, 2017 at 5:49 pm

    Richard Parker, I think you’re right on both accounts. I am a current medical transcriptionist and former insurance claims analyst accustomed to dealing with the similar ICD-9 codes. I read the name to be Daniel as well. The main cause of death I read as “prostatitis complicating peritonitis with prior (I just can’t make out that last word). The code obviously refers to the contributing factor. Even with that in mind, it still helped to have the number which could make the transcription of the bad writing a bit easier. Of course, a little bit of medical terminology knowledge like I have helps a lot, too! 🙂

  • Richard Parker
    May 11, 2017 at 5:33 pm

    I agree with Richard… For cause of death, I see “prostatitis”… not sure about the next word…need more time to examine… and then “peritonitis with paresis”… and another word, that I’m not sure about…. And the contributing cause was “enlarged prostate gland”. In the second picture. the cause of death was myocarditis and the contributing cause was chr. (i.e., chronic) interstitial nephritis, which I have seen often in death records

    • Nancy Freehafer
      May 11, 2017 at 5:35 pm

      I am not sure why Richard Parker’s name appeared in my response. I would have expected the form to let me put my own info in…

  • Richard Parker
    May 11, 2017 at 4:22 pm

    I think the name on the Death certificate is Daniel Adams and not Savil Adams.

    • May 11, 2017 at 8:37 pm

      Thank you Richard, and Joan, for pointing out this possible error. After doing some more research on this person I discovered that you are correct – the name is Daniel – as confirmed by other records. The name in the index is Savill, causing the confusion. Our team has made the correction throughout the article and made note of this correction in the article itself.

  • Richard Parker
    May 11, 2017 at 4:09 pm

    Enlarged Prostate was only a ‘contributing’ factor; it was NOT the cause of death!! The coders made mistakes – lots of them.

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