
By knowing just the first three digits of someone's SSN, you can correctly guess their birthstate. The nine-digit SSN hasbeen used since 1936 to track a person's wages for the purpose of accruingbenefits with the Social Security Administration. The SSN has 3 sections.
Area Numbers
The first three digits ofthe SSN are called the area numbers. This is because they originally corresponded to the state that a personlived in at the time they were issued their SSN.
Beginning in 1972, thearea numbers began being assigned based upon the zip code in the mail addressto which the individual requested his or her card to be sent. Thus, it is possible for someone to reside inone state but ask that the card be returned to another states, thus renderingthe area number less than area specific.
(Click the following image to enlarge it.)

Group Numbers
Digits four and five inthe SSN are referred to as group numbers. They identify the block of numbers currently being issued. As an example, the SSNs 123-01-0001 through123-01-999 would all be issued before moving on to the next group number.
Serial Numbers
Digits six through nineare known as serial numbers. They areissued consecutively from 0001 to 9999.
By dissecting someone'sSSN you can learn the state in which they lived when they applied for the numberfor those SSNs issued prior to 1972 and the state noted in the return addressfor those applied for after 1972.
In some cases, letters mayappear after a social security number . For example, I have a California death certificate that reports a social security number with an "A"appended to the end of the number. For example:"000-00-0000A."
The Social Securitynumber followed by one of these codes is often referred to as a claimnumber. The SSA assigns these codes once someone applies forbenefits. These letter codes may appear on correspondence fromSocial Security or on a Medicare card. They will never appear on a SocialSecurity card.
For example, if thewage earner applying for benefits and your number is 123-45-6789, then theirclaim number is 123-45-6789A. This number isalso be used as their Medicare claimnumber, once they become eligible for Medicare.
Code
Identification
A
Primary claimant (wage earner)
B
Aged wife, age 62 or over
B1
Aged husband, age 62 or over
B2
Young wife, with a child in her care
B3
Aged wife, age 62 or over, second claimant
B5
Young wife, with a child in her care, second claimant
B6
Divorced wife, age 62 or over
BY
Young husband, with a child in his care
C1-C9
Child - Includes minor, student or disabled child
D
Aged Widow, age 60 or over
D1
Aged widower, age 60 or over
D2
Aged widow (2nd claimant)
D3
Aged widower (2nd claimant)
D6
Surviving Divorced Wife, age 60 or over
E
Widowed Mother
E1
Surviving Divorced Mother
E4
Widowed Father
E5
Surviving Divorced Father
F1
Parent (Father)
F2
Parent (Mother)
F3
Stepfather
F4
Stepmother
F5
Adopting Father
F6
Adopting Mother
HA
Disabled claimant (wage earner)
HB
Aged wife of disabled claimant, age 62 or over
M
Uninsured – Premium Health Insurance Benefits (Part A)
M1
Uninsured - Qualified for but refused Health Insurance Benefits (Part A)
T
Uninsured - Entitled to HIB (Part A) under deemed or renal provisions; or Fully insured who have elected entitlement only to HIB
TA
Medicare Qualified Government Employment (MQGE)
TB
MQGE aged spouse
W
Disabled Widow
W1
Disabled Widower
W6
Disabled Surviving Divorced Wife
NOTE: This list is notcomplete, but shows the most common beneficiary codes.
Content for this article is from CR80News Fall 2008 and from the Social Security Administration.