An organized filing system can be arranged in a number of ways including:  Alphabetical, Straight Numeric, or Terminal Digit order.

This article focuses on Terminal Digit filing.

Example of a Terminal Digit System

With Terminal digit filing the last two digits of the filing number determine the primary location of the file.  Then you go to the middle two digits, then the beginning digits  (how many digits depends on the size of the number).

A simple way to describe how to file a six digit number in terminal digit order is: last two, middle two, first two.

For example:  the number 13 76 20 would be filed in the (20) section,  then in order by the (76), then in order by the (13).

You are basically taking the entire file room and dividing it up into 100 sections.  The sections start at (00) and end at (99)

You look at the last two digits first (last two) which means the first section in the file room contain all the numbers that end in (00) and the last section contains all the numbers that end in (99).

Terminal Digit File Room Illustration

00 01 02 03 04 05 06 07 08 09
10 11 12 13 14 15 16 17 18 19
20 21 22 23 24 25 26 27 28 29
30 31 32 33 34 35 36 37 38 39
40 41 42 43 44 45 46 47 48 49
50 51 52 53 54 55 56 57 58 59
60 61 62 63 64 65 66 67 68 69
70 71 72 73 74 75 76 77 78 79
80 81 82 83 84 85 86 87 88 89
90 91 92 93 94 95 96 97 98 99

These sections pretty much stay constant so knowing the last two digits of the filing number means knowing the section of the file room that contains that record (a number ending 50 will be in the middle of the file room etc.).

Now that the record is in the primary section the next digits to file by in that section are the (middle digits). Then you go to the next digits back (first two with a six digit number).


-Very efficient for use in large file rooms

-Records can be filed and retrieved very quickly

-Each section is always in the same area of the file room

-File room personnel learn where each section is located

-Sections fill up evenly because the number sequence is irrelevant

-Works well with randomly purged records

-Shifting of records after a purge is greatly reduced

-Sectioned number easier to deal with

-Color-coding is very efficient

-Makes accessing records difficult for unauthorized personnel

I recommend considering this method of filing if the file room contains 10,000 or more records.


-File room personnel’s fear of learning a new system

-Looking at the filing number basically backwards can be confusing

-Not as efficient for small file rooms

-Not efficient if you have a small number of assigned numbers along with very large files

-More difficult to organize if sub-folders are used

In conclusion, weighing the pros and cons of the various filing methods before starting your filing system will save you lots of future headaches!

Learn how to color-code terminal digit filing!

Click here for staight numeric filing.

Need folders or labels?  Got to efficiency solutions for a great selection of filing products.

>What suggestions can you add to terminal digit filing?

24 Responses to “Analysis of Terminal Digit Filing”

  • jessica says:

    I loved your site it broke it down for me . Thanks for help in writting my paper on filing systems for my class in med. data and coding.

    • Teresa says:


      Thank you for your kind comment. Please let me know if you have any questions as you write your paper.

      Good luck in your class!


      • Susan says:

        Hi Teresa,
        Have you written anything on how to begin this daunting task. We are about to go live with this and wondered if you had any tips we are nearly numbered and have about 50,000 files.. it will be wonderful… just the journey is difficult. We have a very tight area to work in. Kind regards Susan

        • Teresa says:


          Thank you for your question. I would be happy to speak to you on the phone so I can ask you some questions. Hopefully I will be able to offer some suggestions on how to get started. I will send you a direct email with my phone number.



  • Vicki says:

    Great job on explaining this seemingly difficult system. I’ve worked in three hospital systems for over 16 years and just never knew that this filing system had a name to it!!! The book for my class doesn’t explain it as simply as what you did.


  • Chuck says:

    Can you tell me if there is uniformity of color between companies making stickers for both numbers and years for terminal digit filing for radiology files?
    Thanks in advance!

    • Teresa says:


      Thanks for the question about year and numbered labels. Each company that started a color-coded filing system used their own color scheme. Since then label companies have matched the commonly used color schemes to give customers a choice of where to purchase their labels.

      If you are looking to match a particular color scheme let me know and I will see if I can find a match for you.

      Also, feel free to contact me if you have any additional filing system related questions. If you would like to discuss these issues by phone my number is 412-882-1119.



  • Mary says:


    how do you determine which number was issued last in a terminal digit order system?

    Thank you

    • Teresa says:


      I think I understand your question. Terminal digit filing refers to the order that the records are put into the filing system. How the numbers are issued is independent of the filing order. This is actually an advantage to the filing system since records get somewhat evenly placed through out the system.

      To find the last number issued you would need to go back to the source of the number. Today most numbers are assigned by computer so this simplifies the process.

      I hope this answers your question. If not, please feel free to contact me.

      Thank you!


  • Marie says:

    thank you Theresa because i was stocking with my work don’t know what to do i make a lot of mistake then i go to Google and Google it and i find the answer thank you for that because you help me .

  • Khanise says:

    I am taking an office administrative exam and on the practice test it reads:

    In a numeric classification system using terminal digit ordering, which one of the following files would be placed in front of the others?

    A 02-71-18
    B 01-17-21
    C 02-81-17
    D 01-87-21

    C is the correct answer and I am not understanding or clear on why that is. I would appreciate any insight you could give. Thanks.

    • Teresa says:

      Terminal digit filing can be very confusing.

      C is the correct answer because in terminal digit filing you look at the last two digits first, and then the middle digits, then the first two. So the order of the sample numbers would be: C, A, B, D. What I have found helpful in understanding this is to make sure that I only look at two digits at a time, last two, middle two, first two.
      I hope this helps!


  • Lee Spitzer says:

    I am working at a hospital, in medical records. The filing came so easy to me, and still is. I am a think tank, and was wondering if, by any chance, the pairs of numbers, each individually stand for something specific. In a hospital scenario I proposed possibly they might signify body system that was the main focus, place of entrance to hospital (ER, regular admission, etc.)… Is there any validity to this? In working on files from the same day, for instance, I often come across numbers that are similar in two of the pairs, and differ in just the other. Is this merely coincidence?

    • Teresa says:


      This is an interesting question. I also have seen what seem to be patterns in medical record numbers. Every facility has their own numbering system so of course I can not speak for them all. The most common numbering system I have come across in my years working with medical records is a computer system that sequentially assigns numbers to patients that do not already have a number from previous visits. ER visits would more likely be new numbers so the first two digits would have more of a chance to be the same.

      Someone in admissions should be able to tell you how numbers are assigned. Let me know what you find out.


  • Elijah says:

    Thank you so much for this information. I am currently working on a medical records project within a large hospital facility.
    I am planning on introducing the Terminal Digit Filing system to re-issue the patient ID’s for the entire hospital for new patients and old in-coming patient but, I am combining the terminal digit numbering with letters, which is the first two letters of patient’s last name for easier shelf finder.
    Although, I am having a lot of talks and re-orientation with the records staff, I want to be just more informed on current global practice.
    At the moment I am also searching out for standalone server-client software that could help auto-generate these numbers and its barcodes for easier re-assigning to avoid confusion for the records officers. Maybe if you have any idea also on useful applications, I would be glad to know.
    Let me know what you think please.

  • Mercedes says:

    This is very helpful. What happens when there are seven digits? Such as, which of the following columns are in the correct terminal digit order?

    Column C:

    Column D:

    Column E:

    I understand that Column E is in order but there is also another one that’s in order. I’m confused.

    Thanks, Mercedes

    • Teresa says:


      From my understanding of terminal digit filing the only column that is in order is Column E. When you have 7 digits normally you would do last two, middle two, first three. Some filing system administrators may decide to only look at the first two (as the last factor) and let that 7th digit be random.

      Please let me know if you have any additional questions.


  • jen says:

    Hi! In practice test, how do i determine the lowest and highest in terminal digit filing. Example multiple choice:
    a. 22-56-89

    Thanks you in advance.

    • Teresa says:

      Here is the order for your practice test: a,c,d,b. a,c,and d would be filed in the 89 section of your shelving (remember, you have 100 sections that correspond with your last two digits. The next number you look at is the middle two so you put those in order in the 89 section. b ends in 90 so it goes in the 90 section which is the next one after the 89 section on your shelves.

      Please let me know if you need more clarification.

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