She has served in the Russian State Duma as a representative for the Karelia constituency since December 1999, firstly as an independent candidate before joining United Russia in 2000.

Pivnenko was appointed to the Russian Federation Council as a senator of the Republic of Karelia in January 1996 and remained there until March 1997 when her term as a Karelian deputy had concluded.

[2][6] Pivnenko was deputy chair of the Committee on Budget, Tax Policy, Financial, Currency and Customs Regulation and Banking and led an interim commission to investigate Russia's government and the Central Bank of Russia on restricting state short-term liabilities, devaluing the ruble's exchange rate, introducing a ban on foreign exchange transactions of a capital nature.

[6] She was appointed chair of the North of Russia inter-factional group in October 2000 and she led the Karelian regional branch People's Party of the Russian Federation from 2001 to 2003.

During the 2007 Russian legislative election on 2 December that year, Pivnenko won re-election this time as a deputy in the same constituency for the fifth convocation of the State Duma.

She won her fourth re-election to the Karelia constituency this time to the State Duma's fifth convocation during the 2011 Russian legislative election held on 4 December that year.

Pivenko won reelection with a popular vote share of 36.56 per cent and was again appointed first deputy chair of the Committee on Regional Policy and Problems of the North and the Far East.

"[11] That same year, she received the Order of the Holy Equal-to-the-Apostles Princess Olga [ru] "in consideration of helping the Church of the Sign of the Mother of God at Sheremetev Court".

[12] Pivnenko received the Order "For Merit to the Fatherland", Fourth Class in July 2012 "for a great contribution to the development of Russian parliamentarism and active participation in lawmaking.