Listing code
100.04
Children (Part B)
Body system
100.00
Low birth weight and failure to thrive
Subsections
2
Lettered criteria paths
Step in evaluation
3 of 5
Listing match approves the claim
SSA listing text and criteria
Low birth weight in infants from birth to attainment of age 1.
Subsection A
Birth weight (see 100.00B ) of less than 1200 grams. OR
Subsection B
The following gestational age and birth weight: Gestational Age (in weeks) Birth Weight 37-40 2000 grams or less 36 1875 grams or less 35 1700 grams or less 34 1500 grams or less 33 1325 grams or less 32 1250 grams or less
Source: SSA Blue Book listing 100.04. Last synced 2026-05-04.
Where claims under 100.04 usually fail
A common failure mode is using a weight from later after birth instead of the first weight recorded after birth, since birth weight means the first weight recorded after birth. Another pitfall is applying an incorrect threshold, like using 37-40 weeks thresholds for a baby born at 36 weeks under 100.04B. Some people miss the documentation requirement for birth weight because SSA uses an original or certified copy of the infant's birth certificate or a medical record signed by a physician. Another failure mode is filing based on low birth weight outside the covered age window, since this listing is specifically for birth through attainment of age 1.
Medical evidence that strengthens this claim
Birth weight must be documented by an original or certified copy of the infant's birth certificate or by a medical record signed by a physician. SSA treats birth weight as the first weight recorded after birth. If relying on 100.04B, gestational age also needs to be available from the medical record (gestational age is the infant's age based on the date of conception as recorded in the medical record) so the correct gestational age row and birth weight cutoff can be matched. The qualifying evidence is primarily the birth weight and gestational age documentation, rather than growth charts or developmental testing (those are used under 100.05, not 100.04).
What happens if your records do not meet this listing
If the infant does not meet the exact birth weight and (when applicable) gestational age thresholds in 100.04A or 100.04B, the case will move on from this listing. Low birth weight and failure to thrive are evaluated using different listings in this body system, so not meeting 100.04 does not automatically end the claim. For example, failure to thrive is evaluated under 100.05, which uses growth measurements and developmental delay documented within the same consecutive 12-month period. After age 3, growth failure is evaluated under the affected body system(s) rather than under the low-birth-weight listing framework in this section.
Work activity and the SGA gate for this condition
For children under 18 (Part B), the medical basis for this listing is whether the infant's birth weight meets 100.04A (less than 1200 grams) or meets 100.04B when paired with gestational age. SSA uses an original or certified copy of the infant's birth certificate or a medical record signed by a physician, and birth weight is the first weight recorded after birth. If this medical criteria is met, it is evaluated within the age window of birth through attainment of age 1, using the gestational age and birth weight match required by 100.04B (for example, 37-40 weeks with 2000 grams or less, or 36 weeks with 1875 grams or less). If the thresholds are not met for 100.04, other listings in the same body system, such as 100.05 for failure to thrive, may be the next place to focus depending on the documented growth and developmental information.
Listing 100.04 FAQ
Questions that come up repeatedly for low birth weight in infants from birth to attainment of age 1 disability claims.