[1][2] Lapčević served on the executive board of Niš's city government from 2000 to 2004 and was the administrator for Serbia's Nišava District from 2004 to 2008.
Serbia's electoral system was reformed in 2011, such that parliamentary mandates were assigned in numerical order to candidates on successful lists.
Lapčević received the sixteenth position on the DSS's list in the 2014 election, in which the party did not cross the electoral threshold to win representation in the assembly.
[15] He took part in a delegation of DSS and Dveri members to the Republic of Crimea in October of the same year, following the disputed area's de facto joining of the Russian Federation.
The DSS experienced a serious split in November 2016, after which Lapčević, Gorica Gajić, and Dejan Šulkić were the only assembly members to remain with the party.
[20] During the 2016–20 parliament, Lapčević was deputy chair of the parliamentary committee on finance, state budget, and control of public spending; a deputy member of the culture and information committee and the committee on constitutional and legislative issues; a member of the subcommittee for the consideration of reports on audits conducted by the state audit institution; a deputy member of Serbia's delegation to the Parliamentary Assembly of the Organization for Security and Co-operation in Europe (OSCE PA); and a member of the parliamentary friendship groups with Australia, Azerbaijan, Belarus, Bosnia and Herzegovina, China, Georgia, Greece, Iran, Italy, Kazakhstan, North Macedonia, Montenegro, Romania, Russia, Slovenia, and Switzerland.