B-26 — The first 201 planes were ordered based upon design alone.
Prototypes were not characterized with the usual "X" or "Y" designations.
They had Pratt & Whitney R-2800-5 engines.
Armament consisted of two .30 caliber and two .50 caliber machine guns. (
The last model was armed with nearly three times that number.)
Approximate cost then: $80,226.80/aircraft (201 built).

B-26A — Incorporated changes made on the production line to the B-26, including upgrading the two .30 caliber machine guns in the nose and tail to .50 caliber.
A total of 52 B-26As were delivered to the Royal Air Force, which were used as the Marauder Mk I. Approximate cost then: $102,659.33/aircraft (139 built)
B-26B — Model with further improvements on the B-26A, including revised tail gunner's glazing.
Nineteen were delivered to the Royal Air Forces as the Marauder Mk.
IA.
Production blocks of the 1,883 aircraft built:
AT-23A or TB-26B—208 B-26Bs converted into target tugs and gunnery trainers designated JM-1 by the US Navy.

B-26B—Single tail gun replaced with twin guns; belly-mounted "tunnel gun" added. (
81 built)
B-26B-1—Improved B-26B. (225 built)
B-26B-2—Pratt & Whitney R-2800-41 radials. (
96 built)
B-26B-3—Larger carburetor intakes; upgrade to R-2800-43 radials. (
28 built)
B-26B-4—Improved B-26B-3.
 (211 built)
B-26B-10 through B-26B-55 — Beginning with block 10, the wingspan was increased from 65 feet (20 m) to 71 feet (22 m) and flaps were added outboard of the engine nacelle to improve handling problems during landing caused by high wing loads.
The vertical stabilizer height was increased from 19 feet 10 inches (6.05 m) to 21 feet 6 inches (6.55 m).
Armament was increased from six to twelve .50 caliber machine guns; this was done in the forward section so that the B-26 could perform strafing missions.
The tail gun was upgraded from manual to power operated.
Armor was added to protect the pilot and copilot. (
1,242 built)
CB-26B—12 B-26Bs were converted into transport aircraft (all were delivered to the US Marine Corps for use in the Philippines).

B-26C—Designation assigned to those B-26Bs built in Omaha, Nebraska instead of Baltimore, Maryland.
Although nominally the B-26B-10 was the first variant to receive the longer wing, it was actually installed on B-26Cs before the B-26B-10, both being in production simultaneously.
A total of 123 B-26Cs were used by the RAF and SAAF as the Marauder Mk II.
Approximate cost then: $138,551.27/aircraft (1,210 built)
TB-26C—Originally designated AT-23B. Trainer modification of B-26C. (Approximately 300 modified)
XB-26D—Modified B-26 used to test hot air de-icing equipment, in which heat exchangers transferred heat from engine exhaust to air circulated to the leading and trailing edges of the wing and empennage surfaces.
This system, while promising, was not incorporated into any production aircraft made during World War II. (
One converted)
B-26E—Modified B-26B constructed to test the effectiveness of moving the dorsal gun turret from the aft fuselage to just behind the cockpit.
The offensive and defensive abilities of the B-26E was tested in combat simulations against normal aircraft.
Although the tests showed that gains were made with the new arrangement, it was insignificant.
After a cost analysis, it was concluded that the effort needed to convert production lines to the B-26E arrangement was not worth the effort. (
One converted)
B-26F—Angle-of-incidence of wings increased by 3.5º; fixed .50 caliber machine gun in nose removed; tail turret and associated armor improved.
The first B-26F was produced in February 1944.
One hundred of these were B-26F-1-MAs.
Starting with 42-96231, a revised oil cooler was added, along with wing bottom panels redesigned for easier removal.
A total of 200 of the 300 aircraft were B-26F-2s and F-6s, all of which were used by the RAF and SAAF as the Marauder Mk III.
The F-2 had the Bell M-6 power turret replaced by an M-6A with a flexible canvas cover over the guns.
The T-1 bombsight was installed instead of the M-series sight.
British bomb fusing and radio equipment were provided
B-26 — The first 201 planes were ordered based upon design alone. Prototypes were not characterized with the usual "X" or "Y" designations. They had Pratt & Whitney R-2800-5 engines. Armament consisted of two .30 caliber and two .50 caliber machine guns. (The last model was armed with nearly three times that number.) Approximate cost then: $80,226.80/aircraft (201 built).
B-26A — Incorporated changes made on the production line to the B-26, including upgrading the two .30 caliber machine guns in the nose and tail to .50 caliber. A total of 52 B-26As were delivered to the Royal Air Force, which were used as the Marauder Mk I. Approximate cost then: $102,659.33/aircraft (139 built)
B-26B — Model with further improvements on the B-26A, including revised tail gunner's glazing. Nineteen were delivered to the Royal Air Forces as the Marauder Mk.IA. Production blocks of the 1,883 aircraft built:
AT-23A or TB-26B—208 B-26Bs converted into target tugs and gunnery trainers designated JM-1 by the US Navy.
B-26B—Single tail gun replaced with twin guns; belly-mounted "tunnel gun" added. (81 built)
B-26B-1—Improved B-26B. (225 built)
B-26B-2—Pratt & Whitney R-2800-41 radials. (96 built)
B-26B-3—Larger carburetor intakes; upgrade to R-2800-43 radials. (28 built)
B-26B-4—Improved B-26B-3.  (211 built)
B-26B-10 through B-26B-55 — Beginning with block 10, the wingspan was increased from 65 feet (20 m) to 71 feet (22 m) and flaps were added outboard of the engine nacelle to improve handling problems during landing caused by high wing loads. The vertical stabilizer height was increased from 19 feet 10 inches (6.05 m) to 21 feet 6 inches (6.55 m). Armament was increased from six to twelve .50 caliber machine guns; this was done in the forward section so that the B-26 could perform strafing missions. The tail gun was upgraded from manual to power operated. Armor was added to protect the pilot and copilot. (1,242 built)
CB-26B—12 B-26Bs were converted into transport aircraft (all were delivered to the US Marine Corps for use in the Philippines).
B-26C—Designation assigned to those B-26Bs built in Omaha, Nebraska instead of Baltimore, Maryland. Although nominally the B-26B-10 was the first variant to receive the longer wing, it was actually installed on B-26Cs before the B-26B-10, both being in production simultaneously. A total of 123 B-26Cs were used by the RAF and SAAF as the Marauder Mk II. Approximate cost then: $138,551.27/aircraft (1,210 built)
TB-26C—Originally designated AT-23B. Trainer modification of B-26C. (Approximately 300 modified)
XB-26D—Modified B-26 used to test hot air de-icing equipment, in which heat exchangers transferred heat from engine exhaust to air circulated to the leading and trailing edges of the wing and empennage surfaces. This system, while promising, was not incorporated into any production aircraft made during World War II. (One converted)
B-26E—Modified B-26B constructed to test the effectiveness of moving the dorsal gun turret from the aft fuselage to just behind the cockpit. The offensive and defensive abilities of the B-26E was tested in combat simulations against normal aircraft. Although the tests showed that gains were made with the new arrangement, it was insignificant. After a cost analysis, it was concluded that the effort needed to convert production lines to the B-26E arrangement was not worth the effort. (One converted)
B-26F—Angle-of-incidence of wings increased by 3.5º; fixed .50 caliber machine gun in nose removed; tail turret and associated armor improved. The first B-26F was produced in February 1944. One hundred of these were B-26F-1-MAs. Starting with 42-96231, a revised oil cooler was added, along with wing bottom panels redesigned for easier removal. A total of 200 of the 300 aircraft were B-26F-2s and F-6s, all of which were used by the RAF and SAAF as the Marauder Mk III. The F-2 had the Bell M-6 power turret replaced by an M-6A with a flexible canvas cover over the guns. The T-1 bombsight was installed instead of the M-series sight. British bomb fusing and radio equipment were provided
Martin B-26 Marauder