History of Services 11 - 20

Service 11 (1971 - 1988)

Operator	Year	Date	Service changes
ABS	1971	11 April	Introduced between Bedok Rd Ter and Tg Pagar Ter under 1971 Bus Reorganisation.
	1974	3 February	Amended to Upp Changi Rd 8¼ ms (13.3km) Ter under 1974 Bus Rationalisation.
	1975	2 March	Amended to ply Sims Ave and Lor 1 Geylang towards Upp Changi Rd 13.3 km Ter with the conversion of Geylang Rd to one-way traffic.
	1977	23 October	Amended to New Bridge Rd Ter.
	1979	TBC	Relocated to Upp Changi Rd 15.5km Ter.
	1980	15 June	Amended to Somapah Int.
	1986	7 December	Serves new bus stop before Bedok South Ave 3 along Upp East Coast Rd.
	1987	6 June	Amended to relocated New Bridge Rd Ter.
		27 September	Amended to ply the extended Eu Tong Sen St towards Somapah Ter to facilitate the first stage of road expansion along New Bridge Rd.
		1 November	Amended to ply Eu Tong Sen St towards Somapah Ter to facilitate the second stage of road expansion along New Bridge Rd.
	1988	23 October	Withdrawn.

Service 11 (since 1990)

Operator	Year	Date	Service changes
	1990	14 April	Introduced between Lor 1 Geylang Ter and Stadium Blvd (Loop).
	1994	12 June	Amended to ply Stadium Rd before plying Stadium Blvd.
Template:SBS Transit (Current)	2002	8 February	Amended to ply Stadium Walk with the partial closure of Stadium Blvd to facilitate the construction of Stadium MRT station on the Circle MRT Line.
	2004	20 April	Skips bus stop opposite Kallang Care Ctr along Mountbatten Rd.
	2005	5 June	Amended to ply Sims Ave and Sims Way with the partial closure of southbound Mountbatten Rd.
		2 July	Amended to ply Sims Way and Geylang Rd with the partial closure of northbound Mountbatten Rd.
	2006	18 February	Amended to ply Stadium Cres with the full closure of Stadium Blvd to facilitate the construction of Stadium MRT station on the Circle MRT Line.
	2010	29 September	Amended to ply Mountbatten Rd and Stadium Blvd with the closure of Stadium Rd to facilitate the construction of the Singapore Sports Hub.
	2014	8 June	Extended to loop at Rhu Cross under the LTA's Bus Service Enhancement Programme (BSEP).
		29 September	Designated wheelchair-accessible bus service (WAB).
	2017	23 April	Serves bus stops outside and opposite Singapore Indoor Stadium along Stadium Cres/Walk in both directions.

Service 12

Operator	Year	Date	Service changes
ABS	1971	11 April	Introduced between Bedok Rd Ter and Commonwealth Ave Ter under 1971 Bus Reorganisation.
	1974	3 February	Amended to Upp Changi Rd 8¼ ms (13.3km) Ter under 1974 Bus Rationalisation.
	1975	2 March	Amended to ply Sims Ave and Lor 1 Geylang towards Upp Changi Rd 13.3 km Ter with the conversion of Geylang Rd to one-way traffic.
		2 November	Amended to temporary bus terminal along Holland Dr with the partial closure of Commonwealth Ave Ter to facilitate the extension of Commonwealth Ave.
		11 December	Amended to ply New Upp Changi Rd, Bedok Walk, Bedok Plain and Bedok Highway.
	1977	29 August	Amended back to Commonwealth Ave Ter via North Buona Vista Rd.
	1979	TBC	Relocated to Upp Changi Rd 15.5km Ter.
	1980	15 June	Amended to Somapah Int.
		13 July	Amended to ply Commonwealth Ave with the conversion of Queens Circus to a signalised junction, skipping Queensway and Holland Rd.
		28 December	Amended to ply Upp Changi Rd East, skipping Bedok Rd and Upp Changi Rd.
	1982	TBC	Amended to Buona Vista Ter.
	1987	27 September	Amended to ply North Canal Rd and Eu Tong Sen St, skipping Upp Circular Rd.
		13 December	Serves new staggered bus stop opposite Peninsula Plaza along North Bridge Rd, skipping the bus stop outside St Andrew's Cathedral.
	1988	23 October	Extended to Pasir Ris Ter and amended to New Bridge Rd Ter.
	1989	10 December	Amended to Pasir Ris Int.
	1990	22 July	Serves additional bus stop outside Ellenborough Market along Eu Tong Sen St.
	1993	11 April	Amended to ply Jln Sultan, Victoria St, Hill St and New Bridge Rd, skipping South Bridge Rd and Upp Cross St.
	1994	3 July	Amended to ply Kallang Rd and Victoria St, skipping Crawford St, North Bridge Rd and Jln Sultan.
	1997	7 December	Amended to ply Upp Pickering St, South Bridge Rd and Kreta Ayer Rd with the partial closure of New Bridge Rd to facilitate the construction of Chinatown MRT station on the North East MRT Line.
	2001	TBC	Serves new pair of bus stops outside and opposite Lion Home for Elders along Bedok South Rd.
Template:SBS Transit	2002	20 April	Amended to ply the reinstated New Bridge Rd, skipping Upp Pickering St, South Bridge Rd and Kreta Ayer Rd.
	2005	5 June	Amended to ply Sims Ave and Sims Way with the partial closure of southbound Mountbatten Rd.
		2 July	Amended to ply Sims Way and Geylang Rd with the partial closure of northbound Mountbatten Rd.
	2006	3 December	Designated wheelchair-accessible bus service (WAB).
	2014	10 August	Serves new bus stop opposite Blk 2 along Mountbatten Rd.
Template:Go-Ahead Singapore (Current)	2016	18 September	Operations transferred to Go-Ahead Singapore.
	2017	21 October	Serves new pair of bus stops outside Tampines East Stn along Tampines Ave 2.
	2018	10 March	Extended to Kg Bahru Ter with the closure of New Bridge Rd Ter.
		8 April	Serves new pair of bus stops after Somapah Rd and before Simei Rd along Upp Changi Rd East.

Service 12A

Operator	Year	Date	Service changes
	1979	31 December	Introduced between Bedok South Ave 3 and North Bridge Rd (Loop) as a peak hour variant of Service 12 on weekdays.
	1984	2 September	Withdrawn.

Service 13

Operator	Year	Date	Service changes
ABS	1971	11 April	Introduced between Bedok Rd Ter and Commonwealth Ave Ter under 1971 Bus Reorganisation.
		9 May	Amended to ply Upp Changi Rd, Changi Rd, Geylang Rd, Kallang Rd, Crawford St, North Bridge Rd and Stamford Rd.
	1974	3 February	Amended to Upp Changi Rd 8¼ ms (13.3km) Ter under 1974 Bus Rationalisation.
		24 February	Amended to ply Grange Rd, Orchard Blvd and Paterson Rd towards Commonwealth Ave Ter with the conversion of Orchard Rd to one-way traffic.
		1 December	Shortened to Upp Changi Rd Track 6 Ter.
	1975	2 March	Amended to ply Sims Ave towards Upp Changi Rd 13.3 km Ter with the conversion of Geylang Rd to one-way traffic.
		16 November	Amended to Chai Chee Ter.
	1977	6 June	Extended to Ghim Moh Ter.
		19 June	Amended to ply Orchard Blvd and Grange Rd towards Ghim Moh Ter with the full conversion of Orchard Rd to one-way traffic.
	1979	14 October	Amended to ply Sims Ave East towards Chai Chee Ter with the conversion of Changi Rd to one-way traffic.
	1985	8 September	Extended to Bedok Int with the closure of Chai Chee Ter.
	1987	12 April	Shortened to Eunos Ter.
	1989	5 November	Amended to Yio Chu Kang Ter.
		10 December	Amended to Eunos Int.
	1990	2 September	Amended to ply Bishan St 22 and Marymount Rd, skipping Ang Mo Kio Ave 1.
	1996	TBC	Serves additional bus stop outside Kallang Stn along Sims Ave.
	1998	TBC	Extended to Marine Parade Ter with the route amendment of Service 15.
	2001	16 September	Amended to loop at Siglap Rd with the closure of Marine Parade Ter.
Template:SBS Transit (Current)		9 December	Extended to Upp East Coast Ter.
	2003	20 June	Serves new pair of bus stops outside Potong Pasir Stn along Upp Serangoon Rd.
	2009	3 December	Designated wheelchair-accessible bus service (WAB).

Service 13A (1971 - 1974)

Operator	Year	Date	Service changes
ABS	1971	11 April	Introduced between Bedok Rd Ter and Commonwealth Ave Ter under 1971 Bus Reorganisation.
	1974	3 February	Shortened to loop at Mei Chin Rd and re-numbered Service 14 under 1974 Bus Rationalisation.

Short Trip 13A (since 2012)

Operator	Year	Date	Service changes
Template:SBS Transit (Current)	2012	9 April	Introduced from Ang Mo Kio Ave 6 (Aft Blk 304) to Bishan Rd (Bishan Stn) during morning peak hours on weekdays. Wheelchair-accessible at launch.

Service 14

Operator	Year	Date	Service changes
	1974	3 February	Re-numbered from Service 13A as a service between Bedok Rd Ter and Mei Chin Rd (Loop) under 1974 Bus Rationalisation.
		24 February	Amended to ply Grange Rd, Orchard Blvd and Paterson Rd towards Mei Chin Rd with the conversion of Orchard Rd to one-way traffic.
		TBC	Amended to Upp Changi Rd 8¼ ms (13.3 km) Ter.
	1975	2 March	Amended to ply Sims Ave and Lor 1 Geylang towards Upp Changi Rd 13.3 km Ter with the conversion of Geylang Rd to one-way traffic.
	1977	19 June	Amended to ply Orchard Blvd and Grange Rd towards Mei Chin Rd with the full conversion of Orchard Rd to one-way traffic.
	1978	4 September	Amended to ply Nicoll Highway, skipping Sims Ave/Geylang Rd, Kallang Rd/Crawford St and Victoria St/North Bridge Rd.
	1979	TBC	Relocated to Upp Changi Rd 15.5km Ter.
		2 December	Extended to Jln Bt Merah Ter and amended to ply Napier Rd, Holland Rd and Queensway, skipping Tanglin Rd, Alexandra Rd, Stirling Rd, Mei Chin Rd and Mei Ling St.
		23 December	Amended to Bt Merah Central Ter.
	1980	15 June	Amended to Somapah Int.
		28 September	Amended to Bt Merah Int.
	1986	16 March	Amended to ply Stadium Walk.
		13 April	Amended to ply Stadium Rd, skipping Stadium Walk.
		7 December	Serves new bus stop before Bedok South Ave 3 along Upp East Coast Rd.
	1989	5 November	Extended to Changi Village Ter.
	1991	20 January	Shortened to Bedok Int under TransitLink Network Integration Exercise Phase 2.
	1992	29 March	Amended to ply Bt Merah Central.
		TBC	Amended to ply Orchard Link, skipping Grange Rd.
	1993	23 May	Integrated with Service 92 and extended to Clementi Int under TransitLink Network Integration Exercise Phase 13, skipping National Stadium, Tanglin Rd/Orchard Blvd, Napier Rd, Holland Rd and Queensway.
	1994	29 May	Serves 2 new pairs of bus stops outside The Concourse, outside Golden Mile Twr and outside and opposite Suntec City along Nicoll Highway.
	1999	TBC	Skips temporarily abolished bus stops outside and opposite Sch of Mechanical & Mfg along Commonwealth Ave West.
	2001	18 October	Serves reinstated bus stops outside Dover Stn along Commonwealth Ave West.
Template:SBS Transit (Current)	2002	TBC	Serves new staggered bus stop outside Mutiara Crest along River Valley Rd, skipping the bus stop outside Mutiara View.
		7 July	Skips the bus stop opposite Mandarin Singapore along Orchard Rd.
	2004	20 April	Amended to ply Mountbatten Rd, Geylang Rd, Kallang Rd, Victoria St, Jln Sultan and Beach Rd to facilitate reinstatement works for the collapsed Nicoll Highway.
		6 December	Amended to ply the reinstated Nicoll Highway, skipping Mountbatten Rd, Geylang Rd, Kallang Rd, Victoria St, Jln Sultan and Beach Rd.
	2005	12 June	Serves new bus stop outside Science Park along AYE.
		2 July	Amended to ply Grange Rd with the partial closure of Somerset Rd.
	2006	29 October	Amended to Clementi Temp Int.
	2007	TBC	Serves new pair of bus stops outside and opposite Blk 180 along Bedok North Rd.
	2008	14 July	Designated wheelchair-accessible bus service (WAB).
	2011	19 November	Amended to Bedok Temp Int.
		26 November	Amended to Clementi Integrated Transport Hub.
	2012	11 March	Serves new bus stop outside Blk 204 along Bedok North Int.
	2014	10 August	Serves new bus stop opposite Blk 2 along Mountbatten Rd.
		30 November	Amended to Bedok Integrated Transport Hub.
	2018	9 September	Amended to ply North Buona Vista Rd and Commonwealth Ave West, skipping Dover Rd and Dover Ave.

Short Trip 14A

Operator	Year	Date	Service changes
	2000	TBC	Introduced from Bedok Int to Orchard Link (Orchard Theatre) on Sundays and Public Holidays.
Template:SBS Transit (Current)	2004	20 April	Amended to ply Mountbatten Rd, Geylang Rd, Kallang Rd, Victoria St, Jln Sultan and Beach Rd to facilitate reinstatement works for the collapsed Nicoll Highway.
		6 December	Amended to ply the reinstated Nicoll Highway, skipping Mountbatten Rd, Geylang Rd, Kallang Rd, Victoria St, Jln Sultan and Beach Rd.
	2005	2 July	Amended to terminate at Grange Rd (Youth Pk) with the partial closure of Somerset Rd.
	2007	TBC	Serves new bus stop outside Blk 180 along Bedok North Rd.
	2008	14 July	Designated wheelchair-accessible bus service (WAB).
	2011	19 November	Amended to Bedok Temp Int.
	2014	10 August	Serves new bus stop opposite Blk 2 along Mountbatten Rd.
		30 November	Amended to Bedok Integrated Transport Hub.

Service 15 (1975 - 1984)

Operator	Year	Date	Service changes
	1975	22 June	Introduced between Marine Terrace Ter and Prince Edward Ter.
	1976	15 February	Serves new staggered bus stop outside Overseas Union Finance along Robinson Rd.
		14 March	Serves new staggered bus stop outside The Cenotaph along Connaught Dr, skipping the bus stop opposite Singapore Cricket Club.
		4 July	Extended to loop at Shenton Way.
	1978	13 November	Amended to ply Marine Parade Rd and Amber Rd, skipping Joo Chiat Rd and East Coast Rd.
	1979	11 February	Amended to ply the extended Shenton Way, Keppel Rd and Anson Rd, skipping Parsi Rd.
	1981	5 July	Amended to Marine Parade Ter.
		11 October	Serves new staggered bus stop outside Tunas Bldg along Anson Rd, skipping the bus stop outside Intl Plaza.
	1984	16 September	Integrated with Service 196 and withdrawn.

Service 15 (since 1995)

Operator	Year	Date	Service changes
	1995	18 September	Introduced between Pasir Ris Int and Eunos Int with the opening of Temasek Polytechnic.
	1997	5 October	Integrated with Service M4 and extended to loop at Marine Parade Rd.
	1998	TBC	Amended to skip Marine Cres with the route extension of Service 13.
		TBC	Serves new pair of bus stops outside East Coast Apts and before St. Patrick's Rd along Telok Kurau Rd.
	2001	TBC	Serves new pair of bus stops outside and opposite Tropica Condo along Tampines Ave 1.
Template:SBS Transit	2009	3 December	Designated wheelchair-accessible bus service (WAB).
	2011	28 August	Amended to ply Jln Tenaga, Bedok Reservoir Rd and Jln Damai with the partial closure of Kaki Bt Ave 1 to facilitate the construction of Kaki Bukit MRT station on the Downtown MRT Line.
	2013	10 March	Serves additional bus stop opposite Blk 571 along Pasir Ris Dr 1.
	2016	24 April	Amended to ply the reinstated Kaki Bt Ave 1, skipping Jln Tenaga, Bedok Reservoir Rd and Jln Damai.
Template:Go-Ahead Singapore (Current)		18 September	Operations transferred to Go-Ahead Singapore.

Short Trip 15A

Operator	Year	Date	Service changes
Template:SBS Transit (Current)	2009	27 July	Introduced from Pasir Ris Int to Jln Eunos (Opp Eunos Stn) during morning peak hours on weekdays.
		3 December	Designated wheelchair-accessible bus service (WAB).
	2011	28 August	Amended to ply Jln Tenaga, Bedok Reservoir Rd and Jln Damai with the partial closure of Kaki Bt Ave 1 to facilitate the construction of Kaki Bukit MRT station on the Downtown MRT Line.
	2016	24 April	Amended to ply the reinstated Kaki Bt Ave 1, skipping Jln Tenaga, Bedok Reservoir Rd and Jln Damai.
Template:Go-Ahead Singapore (Current)		18 September	Operations transferred to Go-Ahead Singapore.

Service 16

Operator	Year	Date	Service changes
	1976	2 May	Introduced between Marine Terrace Ter and Telok Blangah Heights Ter.
	1981	15 February	Amended to Bt Merah Int.
		5 July	Amended to Marine Parade Ter.
	1983	TBC	Amended to ply Stadium Walk after 1930 hours daily.
	1986	13 April	Amended to ply Stadium Rd, skipping Stadium Walk during the evening diversion into Kallang Park/National Stadium.
	1987	23 February	Amended to Stadium Rd after 1845 hours daily.
	1992	TBC	Amended to ply Orchard Link, skipping Grange Rd.
	1993	23 May	Amended to ply Stadium Rd permanently under TransitLink Network Integration Exercise Phase 13.
		5 December	Integrated with Service 149, extended to loop at Changi Airport and amended to ply Zion Rd/Kim Seng Rd, Outram Rd and Tiong Bahru Rd under TransitLink Network Integration Exercise Phase 14, skipping River Valley Rd, Delta Rd and Lower Delta Rd.
	1994	29 May	Serves 2 new pairs of bus stops outside The Concourse, outside Golden Mile Twr and outside and opposite Suntec City along Nicoll Highway.
	1996	TBC	Converted to bi-directional service between Bt Merah Int and Changi Airport PTB 1.
	1998	6 September	Shortened to Marine Parade Ter with the conversion of Service 36 to a full day trunk service.
	2001	16 September	Amended to loop at Siglap Rd from Bt Merah Int with the closure of Marine Parade Ter.
Template:SBS Transit (Current)	2002	8 February	Amended to ply Stadium Walk and Stadium Cres with the partial closure of Stadium Blvd to facilitate the construction of Stadium MRT station on the Circle MRT Line.
		7 July	Skips the bus stop opposite Mandarin Singapore along Orchard Rd.
	2003	TBC	Serves new bus stop outside Victoria Sch along Marine Parade Rd.
	2004	20 April	Amended to ply Mountbatten Rd, Geylang Rd, Kallang Rd, Victoria St, Jln Sultan and Beach Rd to facilitate reinstatement works for the collapsed Nicoll Highway.
		6 December	Amended to ply the reinstated Nicoll Highway, skipping Mountbatten Rd, Geylang Rd, Kallang Rd, Victoria St, Jln Sultan and Beach Rd.
	2005	2 July	Amended to ply Grange Rd with the partial closure of Somerset Rd.
		30 October	Serves new bus stop outside Blk 94 along Zion Rd.
	2006	18 February	Amended to ply Stadium Cres with the full closure of Stadium Blvd to facilitate the construction of Stadium MRT station on the Circle MRT Line.
		19 March	Amended to ply Cassia Link, Cassia Cres, Guillemard Rd and Guillemard Camp Rd with the partial closure of Old Airport Rd and Dunman Rd to facilitate the construction of Dakota MRT station on the Circle MRT Line.
	2007	19 August	Extended to Bedok Int.
	2008	29 December	Amended to ply the reinstated Old Airport Rd and Dunman Rd, skipping Cassia Link, Guillemard Rd and Guillemard Camp Rd.
	2010	29 September	Amended to ply Mountbatten Rd with the closure of Stadium Rd/Stadium Dr to facilitate the construction of the Singapore Sports Hub.
	2011	19 November	Amended to Bedok Temp Int.
		3 December	Designated wheelchair-accessible bus service (WAB).
	2014	30 November	Amended to Bedok Integrated Transport Hub.
	2017	9 April	Amended to ply Still Rd South and East Coast Rd to facilitate the construction of Marine Parade MRT station on the Thomson-East Coast MRT Line.
		12 November	Amended to ply the reinstated Marine Parade Rd and Joo Chiat Rd, skipping Still Rd South and East Coast Rd.

Service 16E

Operator	Year	Date	Service changes
	1994	31 January	Introduced between Bt Merah Int and Changi Airport as a peak hour uni-directional semi-express service on weekdays.
	1997	1 December	Re-numbered Service 36.

Service 16M

Operator	Year	Date	Service changes
Template:SBS Transit (Current)	2020	9 March	Introduced as a supplementary service between Bedok Intergrated Transport Hub and Bukit Merah Int during mornings and afternoons on weekdays and mornings on Saturdays, plying an extended route of Service 16 via Jln Bukit Merah and Bukit Merah Ctrl. Wheelchair-accessible at launch.

Service 17 (1981 - 1984)

Operator	Year	Date	Service changes
	1981	22 February	Introduced between Changi Point Ter and Prince Edward Rd Ter, operating on weekdays and Saturdays only.
		15 June	Amended to ply Loyang Ave and Loyang Way with the partial closure of Upp Changi Rd.
	1984	8 April	Withdrawn.

Service 17 (since 1993)

Operator	Year	Date	Service changes
	1993	4 April	Introduced between Pasir Ris Int and Bedok Int under TransitLink Network Integration Exercise Phase 12.
Template:SBS Transit	2002	TBC	Converted to loop service between Pasir Ris Int and Bedok Int.
	2009	5 September	Serves new pair of bus stops outside Blk 231A CP and outside Blk 485 along Pasir Ris Dr 4.
	2011	27 June	Designated wheelchair-accessible bus service (WAB).
		19 November	Amended to loop at Bedok Temp Int.
	2014	30 November	Amended to loop at Bedok Integrated Transport Hub.
Template:Go-Ahead Singapore (Current)	2016	18 September	Operations transferred Go-Ahead Singapore and reverted to bi-directional service.
	2017	21 October	Serves new pair of bus stops outside Tampines East Stn along Tampines Ave 2.

Short Trip 17A

Operator	Year	Date	Service changes
Template:SBS Transit	2006	17 April	Introduced from Bedok Int to Bedok North Ave 4 (SBST Bedok Bus Pk) during peak hours on weekdays.
	2011	27 June	Designated wheelchair-accessible bus service (WAB).
		19 November	Amended to Bedok Temp Int.
	2014	16 November	Converted to a full day service between Bedok North Depot and Bedok Temp Int (Loop) under the LTA's Bus Service Enhancement Programme (BSEP). Wheelchair-accessible at launch.
		30 November	Amended to loop at Bedok Integrated Transport Hub.
Template:Go-Ahead Singapore (Current)	2016	18 September	Operations transferred to Go-Ahead Singapore and reverted to a short-trip service from Bedok Integrated Transport Hub and Bedok North Ave 4 (SBST Bedok Bus Pk).

Service 18

Operator	Year	Date	Service changes
	1982	TBC	Introduced between Bedok Int and Tampines Ave 2 (Loop).
	1985	3 November	Amended to loop at Tampines St 22.
	1987	29 November	Extended to start from Tampines Int and loop at Bedok Int, skipping Tampines St 22.
	1999	TBC	Serves new pair of bus stops outside and opposite The Clearwater Condo along Bedok Reservoir Rd.
	2001	TBC	Serves new pair of bus stops opposite Blk 761 and opposite Baywater along Bedok North Ave 3.
Template:SBS Transit (Current)	2006	TBC	Skips a pair of abolished bus stops outside and opposite Bedok Green Sec Sch along Bedok North Ave 3.
	2011	7 March	Designated wheelchair-accessible bus service (WAB).
		19 November	Amended to loop at Bedok Temp Int and amended to ply Bedok North Rd and Bedok North Ave 2.
	2012	11 March	Serves new bus stop outside Blk 204 along Bedok North Int.
	2014	30 November	Amended to loop at Bedok Integrated Transport Hub.
	2016	18 December	Extended to Tampines Concourse Int.
	2017	21 October	Amended to ply Tampines St 32, St 33 and St 34.

Service 19 (1979 - 1981)

Operator	Year	Date	Service changes
	1979	TBC	Introduced between Siglap Rd and Prince Edward Ter.
	1980	12 May	Converted to peak-hour one-directional service on weekdays and Saturdays only.
	1981	11 August	Withdrawn.

Service 19 (1988 - 1990)

Operator	Year	Date	Service changes
	1988	19 June	Introduced between Bedok Int and Pasir Ris Dr 6 (Loop).
	1989	10 December	Amended to Pasir Ris Int.
	1990	10 March	Integrated with Service 4 and withdrawn.

Service 19 (since 1993)

Operator	Year	Date	Service changes
	1993	TBC	Introduced between Tampines Int and Changi Airport Cargo Complex (Loop) as a day service with the permanent amendment of Service 29 to loop at Changi Village Ter.
Template:SBS Transit (Current)	2003	TBC	Serves new pair of bus stops outside and opposite Loyang Ind Est along Loyang Ave.
	2008	TBC	Serves new bus stop outside Changi Beach CP 2 along Nicoll Dr, skipping the bus stop opposite Changi Beach CP 2.
	2011	26 September	Designated wheelchair-accessible bus service (WAB).

Service 20 (1971 - 1989)

Operator	Year	Date	Service changes
STC	1971	11 April	Introduced between Fidelio St Ter and Commonwealth Ave Ter under 1971 Bus Reorganisation.
ABS		6 December	Operations transferred to ABS.
	1973	1 July	Amended to Chai Chee Ter.
	1974	8 December	Amended to ply the extended Robinson Rd, skipping Market St.
	1975	2 March	Amended to ply Sims Ave towards Chai Chee Ter with the conversion of Geylang Rd to one-way traffic.
	1976	15 February	Serves new staggered bus stop between Bank of India and Hong Leong Holdings along Robinson Rd.
	1977	7 March	Extended to Ghim Moh Ter.
	1978	15 January	Amended to ply Jln Sultan, skipping Sumbawa Rd.
	1979	11 February	Amended to ply the extended Shenton Way towards Ghim Moh Ter, skipping Parsi Rd and Anson Rd.
		14 October	Amended to ply Sims Ave East towards Chai Chee Ter with the conversion of Changi Rd to one-way traffic.
	1981	11 October	Serves new staggered bus stop outside Tunas Bldg along Anson Rd, skipping the bus stop outside Intl Plaza.
	1985	8 September	Extended to Bedok Int with the closure of Chai Chee Ter.
	1988	3 January	Serves new staggered bus stop opposite Treasury Bldg along Shenton Way, skipping the bus stop opposite Marina House.
	1989	5 November	Integrated with Service 100 and withdrawn.

Service 20 (1994 - 2000)

Operator	Year	Date	Service changes
	1994	TBC	Introduced between Sims Pl Ter and St. Wilfred Rd (Loop).
	2000	27 November	Integrated with Service 125 and withdrawn.

Service 20 (since 2013)

Operator	Year	Date	Service changes
Template:SBS Transit (Present)	2013	9 June	Introduced between Tampines Int and Changi Business Park Central 2 (Loop) under the LTA's Bus Service Enhancement Programme (BSEP).
		30 September	Designated wheelchair-accessible bus service (WAB).
	2015	20 December	Serves new pair of bus stops outside and opposite Changi City Point along Changi South Ave 2.
	2017	21 October	Amended to ply Somapah Rd and Changi South Ave 1, skipping Upp Changi Rd East and Xilin Ave.
	2018	10 June	Serves new pair of bus stops outside and opposite The Eightrium along Changi South Ave 1.