How many books are in the Sigma Force series?

There are 19 books in the Sigma Force series.

When will the next book in the Sigma Force series be released?

The Sigma Force series does not have a new book coming out soon. The latest book, The Last Odyssey (Book 15), was published in March 2020.

The first book in the Sigma Force series, Sandstorm, was published in July 2004.

Order	Book	Genre	Date	Rating
1	Sandstorm	Thriller / T	2004-07 / Jul-2004	4-5 /
2	Map of Bones	Thriller / T	2005-05 / May-2005	4-5 /
3	Black Order	Thriller / T	2006-07 / Jul-2006	4-5 /
3.5	Kowalski's in Love (ss)	Thriller / T	2006-06 / Jun-2006	3-5 /
4	The Judas Strain	Thriller / T	2007-07 / Jul-2007	4 /
5	The Last Oracle	Thriller / T	2008-07 / Jul-2008	4-5 /
6	The Doomsday Key	Thriller / T	2009-07 / Jul-2009	4-5 /
7	The Devil Colony	Thriller / T	2011-07 / Jul-2011	4-5 /
8	Bloodline	Thriller / T	2012-07 / Jul-2012	4-5 /

9	The Eye of God	Thriller / T	2013-06 / Jun-2013	4-5 /
10	The Sixth Extinction	Thriller / T	2014-09 / Sep-2014	4-5 /
10.5	The Midnight Watch (e)	Thriller / T	2015-11 / Nov-2015	0 /
11	The Bone Labyrinth	Thriller / T	2015-12 / Dec-2015	5 /
11.5	Crash and Burn (e)	Thriller / T	2016-11 / Nov-2016	5 /
12	The Seventh Plague	Thriller / T	2016-12 / Dec-2016	5 /
12.5	Ghost Ship (e)	General Fiction / GF	2017-10 / Oct-2017	0 /
13	The Demon Crown	Thriller / T	2017-12 / Dec-2017	4-5 /
14	Crucible	Thriller / T	2019-01 / Jan-2019	3-5 /
15	The Last Odyssey	Thriller / T	2020-03 / Mar-2020	5 /