Fields was chosen to represent this district in a special election held on March 9, 2004, due to incumbent Steve Levy's resignation to become Suffolk County Executive.[2] She was re-elected in 2006 and again in 2008, when she defeated Republican opponent John Bugler. In September 2010, she lost the Democratic primary race to Ken Mangan.[3] Fields ran in the 2010 general election on the Independence and Working Families party lines, but was defeated by Republican Al Graf.[4]
Fields previously served as a lawmaker in the Suffolk County Legislature (2000–2003), where she chaired the Health Committee. Prior to her election to the legislature she served as a health care administrator for 37 years.