Series Letters in Serial Numbers (Series 1996 and Later)
On redesigned $5 to $100 notes the first serial-number letter stands for the series year. The table from A (1996) to M (2013), and what to know about later letters.
At a glance
- Applies to: $5, $10, $20, $50, $100 from each note's first redesign onward
- Not on: $1 and $2, which keep the single-letter format
The table
- A — Series 1996
- B — Series 1999
- C — Series 2001
- D — Series 2003
- E — Series 2004
- F — Series 2003A
- G — Series 2004A
- H — Series 2006
- I — Series 2006
- J — Series 2009
- K — Series 2006A
- L — Series 2009A
- M — Series 2013
- N, P, Q — Series 2017, 2017A and 2021 according to collector references; the BEP table we could open stops at Series 2013
Series year versus printing year
The series year printed on a note is the year its design or signatures were adopted, not the year it was printed. A suffix letter after the year, such as 2017A, marks a change of Treasurer or Secretary signatures within the same design.
FAQ
My $1 bill has one letter; which series is it?
Read the series year printed on the face, next to the portrait; the single serial letter is the bank, not the series.
Why are I and O treated differently?
I is used as a series letter (Series 2006 on some denominations), while O is skipped because it looks like zero.
Related
Sources
Updated 2026-09-11.