Pacific Theatre operations

After initial shakedown exercises off the U.S. East Coast, Mack assembled with ComCortDiv 82 at Norfolk, Virginia, 17 to 20 October 1944, and departed on 21 November for the Panama Canal en route to the Pacific Ocean. Becoming a unit of the U.S. 7th Fleet Mack escorted convoys between Hollandia, New Guinea, Kossol Roads, Palau Islands, and Leyte until March 1945. On 2 March she commenced antisubmarine patrols in the South China Sea off the Philippines. Investigating sonar contact on 13 March, Mack grounded on an uncharted shoal in Mangarin Bay, damaging both screws and tall shafts. Towed to Hollandia for repairs, which lasted from 14 April to 4 June, she returned to escort duty between Hollandia and Manila on 14 June.

A month later Mack commenced working for the port director, Manila, escorting ships to San Fernando, Luzon, until 3 August when she was placed under the authority of the port director, Subic, and escorted a convoy of landing craft from Subic Bay to Okinawa.

End-of-war activity

Two days after the signing of the surrender terms, Mack began air-sea rescue patrols between the Philippines and the Palaus, returning to escort duty on 16 August to accompany a slow tow through the “typhoon belt" to Okinawa. Completing that assignment, she commenced air sea rescue patrols east of Samar, Philippine Islands.

Relieved of this duty on 6 December, Mack got underway for Okinawa and Shanghai on 8 December, returning to Subic Bay on 27 December.

Collision at sea

While standing by for escort duty at San Fernando, 10 January 1946, Mack answering a distress call from FS-74, proceeded through heavy weather to the disabled ship's position. In the course of passing much needed food and water to the crew of FS-74, the two ships collided, causing damage to Mack's bow (11 January). Mack returned to San Fernando and escorted the waiting ships to Subic Bay, remaining at Subic for three weeks undergoing repairs and holding drills.

Operations in the China area

Departing Subic Bay 11 February, Mack joined Escort Division 33 and set course for Qingdao, China, where the U.S. 7th Fleet was lending support to the U.S.-China policy; standing by to protect, if necessary, American interests during the fighting between the Nationalist forces and the Communists. Arriving on 20 February, Mack took part in training exercises off the China coast and made brief trips to Shanghai and Taku before departing Chinese waters on 15 April, for Okinawa to take on naval passengers en route to the United States.

Arriving at San Pedro, Los Angeles on 11 May 1946 Mack debarked her passengers, unloaded her ammunition and began undergoing a period of inactivation and preservation.

Post-war decommissioning

Mack was placed out of commission in reserve on 11 December 1946 at San Diego, California. She was placed in the Pacific inactive Fleet, berthed at Mare Island, California. On 15 March 1972 she was struck from the Navy list, and, on 13 June 1973, she was sold for scrap.