About CasualtyBase

Where these records come from

During the Second World War, every time a U.S. Army soldier was admitted to hospital, the details were written down in code on a punch card. Millions of those cards survive. CasualtyBase turns them back into plain English.

The journey of the cards

1942–1945 A card for each admission
Each hospital admission was summed up on a coded card for the Army’s Office of the Surgeon General, which used the cards to keep medical statistics.
Later years Moved onto computer tape
The cards were copied onto magnetic tape, which was later held by the National Research Council’s Medical Follow-up Agency.
1973 · 1988 A second life after the fire
A 1973 fire at the National Personnel Records Center destroyed millions of service files. In 1988 the Center obtained the tapes — 46 reels, over 10 million records — to help rebuild veterans’ medical histories.
Today Released by the National Archives
The National Archives publishes the files for anyone to use, after hiding a small set of sensitive medical details.
Now Searchable in CasualtyBase
CasualtyBase reads the 1942–1945 files, translates every code and lets you look up a soldier by service number.

What a card looks like

This is one real card, exactly as it appears in the National Archives file. Every position on the line has a meaning; the numbered parts are translated below.

000000176T0000176512718135-324147940025284420132234808523399760239- 4351014045435036&

1 Service number T-176
2 Rank Warrant officer or flight officer
3 Age 27
4 Arm of service Air Force, troop carrier units
5 Where and which day –3 = North Africa, Italy, Sicily and nearby; 24 = admitted on the 24th
6 Month and year 1 = January, 4 = 1944
7 Type of case Battle casualty
8 Diagnosis Simple fracture of the fibula (lower leg)
9 Operation Amputation of the lower leg
10 Cause Crash, the result of enemy gunfire
11 Days lost 435 days
12 Outcome Discharged or retired
13 Left hospital 4 = April, 5 = 1945

Read together, this card says: a 27-year-old flight officer with a troop carrier unit was hurt in a crash caused by enemy gunfire and admitted in the Mediterranean on 24 January 1944. He was treated for a broken lower leg and had an amputation; after 435 days he left hospital in April 1945 and was discharged.

What a card tells you

Service number, rank, age, race (as the Army recorded it) and branch of service
When he was admitted, and often when he left
Where: a camp or fort in the United States, or a theater of war overseas
Diagnosis, the part of the body affected and any operations
For injuries: the cause and the circumstances
Days lost from duty, and the outcome — back to duty, discharged or died

What a card does not tell you

No names. The service number is the only way to find a person.
Some details are withheld. The National Archives hides mental-health, psychiatric and venereal-disease diagnoses. CasualtyBase marks these as “Withheld by NARA”.
Not every hospital stay. Battle casualties were all recorded, but other admissions were only sampled (80% or 20%), so a missing card does not mean a soldier was never in hospital.
No exact battlefield location. Overseas admissions usually name only a region, such as “European Theater of Operations”.

How many cards

Admission cards in each year’s file, split by type of case. 1944 holds over half of all cards; its many “not recorded” cards simply had no type of case filled in.

1942 203,796
1943 711,725
1944 3,547,186
1945 2,041,146

Disease
Non-battle injury
Injury (battle status not recorded)
Battle casualty or injury
Not recorded

Show as table

File	Disease	Non-battle injury	Injury (battle status not recorded)	Battle casualty or injury	Not recorded	Total
1942	171,313	0	20,531	11,952	0	203,796
1943	474,568	0	107,673	129,484	0	711,725
1944	1,340,902	264,763	0	567,728	1,373,793	3,547,186
1945	1,165,313	156,372	0	718,602	859	2,041,146

How CasualtyBase reads the cards

Cut each line into fields. The Army changed its card layout from year to year — there are 19 different layouts. We use the National Archives’ layout charts to find where each piece of information sits.
Translate the codes. Numbers like “023” become “Crash, result of enemy gunfire”, using the Army’s own code lists and the decoding programs written by the Records Center in 1988.
Put it in everyday words. Each year named things differently, so we map every card onto one set of headings: when, where, diagnosis, cause, outcome.
Group a soldier’s cards. All cards with the same service number appear on one timeline, in date order. Identical copies are shown once.
Check the results. Automated tests compare our output with real cards, and patterns are checked against common sense — for example, no one is admitted on 31 April.

Judgement calls we make

Old records are not always clear. Where we have to interpret, these are the rules we follow.

Exact dates. Most cards give only a month and year. On many 1944 and 1945 cards the day is tucked into the place code, as the National Archives documentation describes; we show it only when that date exists in the calendar.
“About” dates. When we know the admission day, we add the days lost to estimate when he left hospital — and show it only if it falls in the month the card records.
Deaths. On 1942–1943 cards the code for “died” was often lost. A diagnosis such as “killed in action” counts as a death.
Battle-casualty cards. Some 1942–1943 cards were printed for battle casualties but record a disease; we count those as disease. The rest have no type-of-case code, so we count them as battle casualties because of the card they were filed on.
Similar numbers. Service numbers were sometimes typed with a missing prefix or digit. Close matches are listed separately as “similar”, since they are probably different men.

Find out more

The original files and their documentation are in the National Archives catalog: Hospital Admission Card Files (Record Group 112, Records of the Office of the Surgeon General, Army).
The National Archives at St. Louis offers look-ups of individual cards.
Need a service number? Search enlistment records by name at wwii-enlistment.com.