Earlier this month, the 'Milkshake' singer was targeted by the institution after failing to pay $330,426 (£210,910) in New York state taxes from 2004 and 2010.
Kelis now also owes separate payments of $61,737.29 (£39,852.18) and $213,932.02 (£138.095.78) in taxes in California for the years 2009 and 2010, according to court documents obtained by TMZ.
This brings the reported total of the performer's government debt to $606,096.12 (£391,259.12) in unpaid taxes.
Best known for her 2003 album Tasty, the 32-year-old recently debuted a new track titled 'Distance'.
Kelis has yet to comment publicly on the situation.