The Heer had several different types of penal units and we have explained the different ones below.

Bewährungseinheiten

The below battalions (bewährungseinheiten) consisted of soldiers who were condemned to probation. These units were supplied and treated nearly as normal units but used for special dangerous "missions". Usually these soldiers had to make their probation in their field unit and were transferred to these Inf.Btls.z.b.V. when their unit was not at the front or did no actions where the soldiers could stand the test. The units were normally used as Heerestruppen instead of being part of a division or lower unit.

Grenadier-Bataillon z.b.V. 291 was formed in September 1944. It ended the war with the 19. Armee.

Grenadier-Bataillon z.b.V. 292 was formed in September 1944. It ended the war with the 19. Armee.

Grenadier-Bataillon z.b.V. 540 was formed in October 1942 from the redesignation of Infanterie-Bataillon 540 z.b.V. It was stationed on the northern sector of the Eastern Front and ended the war with the 18. Armee.

Grenadier-Bataillon z.b.V. 550 was formed in October 1942 from the redesignation of Infanterie-Bataillon 550 z.b.V. It was stationed on the central sector of the Eastern Front and retreated through Poland before ending the war in East Prussia with 3. Panzerarmee.

Grenadier-Bataillon z.b.V. 560 was formed in October 1942 from the redesignation of Infanterie-Bataillon 560 z.b.V. It was stationed on the southern sector of the Eastern Front and retreated through Poland before ending the war in East Prussia with 4. Armee.

Grenadier-Bataillon z.b.V. 561 was formed in January 1944 from the redesignation of Infanterie-Bataillon 561 z.b.V. It was stationed on the northern sector of the Eastern Front and ended the war with the 18. Armee.

Infanterie-Bataillon 491 z.b.V. was formed in November 1944 by Heeresgruppe Nord and was later transferred to Heeresgruppe Kurland.

Infanterie-Bataillon 500 z.b.V. was the first penal battalion. It was formed in Fulda in June 1941 as Bewährungs-Bataillon 500.

Infanterie-Bataillon 540 z.b.V. was formed in Fulda in December 1941. It was redesignated Grenadier-Bataillon z.b.V. 540 in October 1942.

Infanterie-Bataillon 550 z.b.V. was formed in Fulda in November 1941. It was redesignated Grenadier-Bataillon z.b.V. 550 in October 1942.

Infanterie-Bataillon 560 z.b.V. was formed in Fulda in August 1942. It was redesignated Grenadier-Bataillon z.b.V. 560 in October 1942.

Infanterie-Bataillon 561 z.b.V. was formed in Skierniewice in January 1943. It was redesignated Grenadier-Bataillon z.b.V. 560 in January 1944.

Wehrunwürdig / 999

The 999 units were made up of men seen as not "worthy to serve" (Wehrunwürdig), so they were not condemned in a court. The men included men assigned there for political reasons but also many others.

999. Leichte Afrika Division (also known as 999. Afrika Division) was formed from Afrika-Brigade 999. The 999 units that were part of those units are not included in the below list.

Verstärktes Afrika-Regiment 361 was made up of Germans who previously served in the French Foreign Legion and was a part of the 90. Leichte Afrika-Division.

Afrika-Schützen-Regiment (mot) 961 was part of Afrika Brigade 999 and later 999. Leichte Afrika Division.
Afrika-Schützen-Regiment (mot) 962 was part of Afrika Brigade 999 and later 999. Leichte Afrika Division.
Afrika-Schützen-Regiment (mot) 963 was part of Afrika Brigade 999 and later 999. Leichte Afrika Division.

Artillerie-Abteilung (mot) 961 was part of Afrika-Schützen-Regiment (mot) 961, see above.
Artillerie-Abteilung (mot) 962 was part of Afrika-Schützen-Regiment (mot) 962, see above.
Artillerie-Abteilung (mot) 963 was part of Afrika-Schützen-Regiment (mot) 963, see above.

Ersatz-Bataillon 999 was formed in February 1943 and was a replacement unit for the penal units. It was disbanded in September 1944. It is also referred to as Ersatz-Brigade 999 in some sources.

Einsatz-Bataillon 999 was formed in September 1944 from the disbanded Ersatz-Bataillon 999 and was used for construction work.

I. Festungs-Infanterie-Bataillon 999 was formed in June 1943 by the redesignation of III./Afrika-Schützen-Regiment 961. It was was stationed in Greece with 41. Festungs-Division and later in the Crimea where it was destroyed in May 1944.
II. Festungs-Infanterie-Bataillon 999 was formed in June 1943 by the redesignation of III./Afrika-Schützen-Regiment 962. It was stationed in Greece with 41. Festungs-Division and in January 1945 was absorbed by the Grenadier-Regiment 1232 when the division was reformed into the 41. Infanterie-Division.
III. Festungs-Infanterie-Bataillon 999 was formed in June 1943 by the redesignation of I./Afrika-Schützen-Regiment 963. It was stationed in Greece with 41. Festungs-Division and in January 1945 was absorbed by the Grenadier-Regiment 1232 when the division was reformed into the 41. Infanterie-Division.
IV. Festungs-Infanterie-Bataillon 999 was formed in June 1943 by the redesignation of II./Afrika-Schützen-Regiment 963. It was stationed in Greece with 41. Festungs-Division and in January 1945 was absorbed by the Grenadier-Regiment 1232 when the division was reformed into the 41. Infanterie-Division.
V. Festungs-Infanterie-Bataillon 999 was formed in June 1943 by the redesignation of III./Afrika-Schützen-Regiment 963. It was used as Heerestruppen and was stationed in the Balkans.
VI. Festungs-Infanterie-Bataillon 999 was formed in June 1943 by Aufstellungsstab Heuberg. It was used as Heerestruppen and later attached to Strum-Division Rhodos.
VII. Festungs-Infanterie-Bataillon 999 was formed in June 1943 by Aufstellungsstab Heuberg. It was used as Heerestruppen and was stationed in the Balkans.
VIII. Festungs-Infanterie-Bataillon 999 was formed in June 1943 by Aufstellungsstab Heuberg. It was used as Heerestruppen and was stationed in the Balkans.
IX. Festungs-Infanterie-Bataillon 999 was formed in June 1943 by Aufstellungsstab Heuberg. It was used as Heerestruppen and was stationed in the Balkans.
X. Festungs-Infanterie-Bataillon 999 was formed in June 1943 by Aufstellungsstab Heuberg. It was used as Heerestruppen and was stationed in the Balkans until it was disbanded in the end of 1944.
XI. Festungs-Infanterie-Bataillon 999 was formed in June 1943 by Aufstellungsstab Heuberg. It was used as Heerestruppen and was stationed in the Balkans.
XII. Festungs-Infanterie-Bataillon 999 was formed in June 1943 by Aufstellungsstab Heuberg. It was used as Heerestruppen and was stationed in the Balkans.
XIII. Festungs-Infanterie-Bataillon 999 was formed in July 1943 by Aufstellungsstab Heuberg. It was used as Heerestruppen and was stationed in the Balkans.
XIV. Festungs-Infanterie-Bataillon 999 was formed in July 1943 by Aufstellungsstab Heuberg. It was used as Heerestruppen on the Eastern Front and was destroyed at Tighina in Romania in August 1944.
XV. Festungs-Infanterie-Bataillon 999 was formed in July 1943 by Aufstellungsstab Heuberg. It was used as Heerestruppen on the Eastern Front and was destroyed in at Leontina in Romania in August 1944.
XVI. Festungs-Infanterie-Bataillon 999 was formed in July 1943 by Aufstellungsstab Heuberg. It was used as Heerestruppen and was stationed in the Balkans.
XVII. Festungs-Infanterie-Bataillon 999 was formed in July 1943. It was used as Heerestruppen on the Eastern Front and was destroyed in at Tiraspol in Romania in August 1944.
XVIII. Festungs-Infanterie-Bataillon 999 was formed in December 1943. It was used as Heerestruppen and was stationed in the Balkans until it was disbanded in the end of 1944.
XIX. Festungs-Infanterie-Bataillon 999 was formed in January 1944. It was used as Heerestruppen and was stationed in the Balkans until it was destroyed in December 1944.
XX. Festungs-Infanterie-Bataillon 999 was formed in February 1944. It was used as Heerestruppen and was stationed in the Balkans. In April 1945 it was reformed into Festungs-Infanterie-Bataillon 1483.
XXI. Festungs-Infanterie-Bataillon 999 was formed in June 1944. It was used as Heerestruppen and was stationed in the Balkans.
XXII. Festungs-Infanterie-Bataillon 999 was formed in July 1944. It was used as Heerestruppen and was stationed in the Balkans.
XXIII. Festungs-Infanterie-Bataillon 999 was formed in August 1944. It was used as Heerestruppen and was stationed on the Western Front.

Landesbau-Bataillon 999 was formed in August 1943, redesignated Landesbau-Pionier-Bataillon 999 z.b.V. 999 in October 1943, Stellungsbau-Pionier-Bataillon I./999 in December 1943 and finally Bau-Pionier-Bataillon I./999 in June 1944. It was assigned to 18. Armee in 1944 and ended the war with 6. Panzerarmee.
Stellungsbau-Pionier-Bataillon II./999 was formed in December 1943 and was redesignated Bau-Pionier-Bataillon II./999 in June 1944.
Bau-Pionier-Bataillon III./999 was formed in July 1944 and was assigned to 15. Armee.
Bau-Pionier-Bataillon IV./999 was formed in July 1944 and was assigned to 1. Armee.    

Strafgefangenen-Abteilungen

The (Feld-) Strafgefangenen-Abteilungen consisted of soldiers which were condemned to prison for longer than 3 months (for specific crimes) and were used for hard, dangerous labour for example in partisan endangered areas.

Strafvollstreckungszüge

The Strafvollstreckungszüge of divisions and armies consisted of soldiers condemned to prison for less than 3 months (for specific crimes).

Feld-Sonder-Bataillone

The Feld-Sonder-Bataillone consisted of soldiers who had served their time but were not accepted back into in their field unit because of deficiencies in character.

Sources used

Research by Christoph Awender
Georg Tessin - Verbände und Truppen der deutschen Wehrmacht 1933-1945

Reference material on these units

Hans Burckhardt & Günter Erxleben - Strafdivision 999: Erlebnisse und Berichte aus dem antifaschistischen Widerstandskampf
Hans Burckhardt, Günter Erxleben & Kurt Nettball - Die mit dem blauen Schein: Über den antifaschistischen Widerstand in den 999er Formationen der faschistischen deutschen Wehrmacht (1942–1945)
Peter Czyba - Odyssee Eines 999ers: Die Erlebnisse eines jungen deutschen Soldaten des Strafbataillons 999, den es auf abenteuerlichen Wegen von Ruland ber Tunesien nach Amerika verschlug
Hans-Peter Klausch - Die 999er: Von der Brigade „Z“ zur Afrika-Division 999. Die Bewährungsbataillone und ihr Anteil am antifaschistischen Widerstand.
Hans-Peter Klausch - Die Geschichte der Bewährungsbataillone 999 unter besonderer Berücksichtigung des antifaschistischen Widerstandes