The 1934 J US $20 bill is a highly collectible note and its value can vary greatly depending on its condition and rarity. On average, a circulated 1934 J $20 bill in good condition can be worth anywhere from $1,000 to $2,500. A note in uncirculated condition can be worth significantly more, potentially reaching values of $5,000 or higher. The rarity and desirability of the J series $20 bill contribute to its value, making it a sought-after item among collectors.