There was an initial requirement for 220 tank destroyer battalions, but the troop basis for 1943 called for only 144. Only a maximum of 106 battalions were ever active at one time, and the number required was trimmed to 78 in October 1943. Eleven tank destroyer battalions were converted to other types of units. Twenty-five were inactivated; five in 1943, fourteen in 1944, and four in 1945. The units converted were chiefly trained as amphibian tractor and armored field artillery battalions, presumably because of their previous experience with heavy tracked vehicles. The units inactivated, particularly those in 1944, were given brief retraining as infantry and dispatched overseas as replacements or to depleted infantry divisions for use as fillers. Sixty-one battalions went to Europe, North Africa and the Mediterranean, and ten to the Pacific, one of which was converted after arrival, technically making nine, and counting towards the eleven described above.

The 627th, 632nd, 637th, 640th, 641st, 670th, 671st, 806th, 815th, and 819th Tank Destroyer Battalions deployed to the Pacific Theater. The 815th, quickly found to be essentially useless in dense jungle warfare (information on this battalion is particularly sparse), was disbanded and its personnel (including noted author Norman Mailer) absorbed by the 112th Cavalry Regiment after a short experience on New Guinea. The 641st was converted to a chemical mortar battalion, and the 627th, 670th, 671st and 806th failed to get into action before the war ended.

M18s served on Okinawa, but curiously not part of any tank destroyer battalions. General Andrew D. Bruce, the original commander of the Tank Destroyer Tactical and Firing Center, ended up in command of the 77th Infantry Division, and managed to secure eight M18s to re-equip the anti-tank company of the 306th Infantry Regiment.

632nd Tank Destroyer Battalion (M10)

Established 15 December 1941 at Camp Livingston, LA from personnel of the 32nd Infantry Division. Originally a Light Towed Battalion, they shipped from San Francisco, port of embarkation on May. 12, 1942 and arrived in Australia on May 12, 1942. Landed New Guinea on Oct 28, 1943. Landed Philippines on Oct. 20, 1944. The 632nd Tank Destroyer Battalion was, essentially, treated as an organic unit of the 32nd Division. It went to Australia with the 32nd Division. It fought with the 32nd at Aitape and Saidor. It went into the battle for Leyte with the 1st Cavalry Division, but later joined the 32nd on Leyte. On Luzon it was initially attached to the 13th Armored Group but subsequently served with 37th, 44th [sic] and 32nd Divisions on Luzon. Unit was deactivated at Camp Stoneman, CA on Jan. 1, 1946.

637th Tank Destroyer Battalion (M18)

Established December 19, 1941 at Camp Shelby, MS from personnel of the 37th Infantry Division. Originally a Light Towed Battalion, they shipped from San Francisco, port of embarkation on May. 12, 1942 and arrived in Australia on May 26, 1942. Arrived Fiji Islands on June 28, 1942. Unit was attached to the 11th Airborne Div., 1st Cavalry and 37th Infantry Div. Inactivated in Japan on Jan. 25th, 1946.

640th Tank Destroyer Battalion (M5 3-inch gun; to M10 October 1944)

Established December 19, 1941 at Camp San Luis Obispo, CA, from personnel of the 143rd Field Artillery California National Guard. Originally a Light Towed Battalion, they shipped from San Francisco, port of embarkation on Sep. 4, 1942 and arrived in Hawaii on Sep. 12, 1942. Arrived Guadalcanal on Feb. 5, 1944, New Britain on May 3, 1944 and the Philippines on Jan. 9, 1945. Unit was attached to the 1st Cavalry, 24th, 43rd & 44th [sic] Infantry Divs. Inactivated on Jan. 13th 1946 at Camp Anza, CA

641st Tank Destroyer Battalion (n/a)

Established December 18, 1941, at Ft Lewis, WA, from personnel of the 41st Infantry Division. Originally a Light Towed Battalion, they shipped from the New York port of embarkation on Mar. 4, 1942, and arrived in Australia (via the Panama Canal) on Apr. 9, 1942. Arrived New Guinea on Jan. 21, 1943. Entered combat in May, 1944, and were redesignated as 98th Chemical Battalion (Motorized) on Jun. 24, 1944. Landed in the Philippines on Jan. 9, 1945, and were redesignated as 98th Chemical Mortar Battalion on Mar. 20, 1945. Returned to U.S., landing at Los Angeles Port on Dec 24, 1945. Deactivated on Dec. 26, 1945, at Camp Anza, CA.

815th Tank Destroyer Battalion (various sources list this unit as either having M5 3-inch guns or M10s; again, information is hard to come by)

Formed on May 11, 1942, at Camp Cooke, CA, as a Heavy Self-Propelled unit. Sailed from San Francisco port on Mar. 10, and landed New Guinea on Mar. 30, 1944. Disbanded on Sept. 27, 1944.

819th Tank Destroyer Battalion (M10)

Activated on June 1, 1942 at Camp Chaffee, AR as a Heavy Self-Propelled unit. Shipped from San Francisco port of embarkation on Mar. 15, 1944 and landed in Hawaii on Mar. 21, 1944. Landed Palau on Feb. 1, 1945.

Sources:

Gabel, Christopher R. Seek, Strike, and Destroy: U.S. Army Tank Destroyer Doctrine in World War II. Fort Leavenworth: Combat Studies Institute Press, 1985.

tankdestroyer.net

Wiggins, Robert P. Jungle Combat with the 112th Cavalry: Three Texans in the Pacific in World War II. Jefferson: McFarland & Company, 2011.

Yeide, Harry. The Tank Killers: A History of America's World War II Tank Destroyer Force. Drexel Hill: Casemate Publishers, 2007.