6 May 1805 Hospital Mate.
12 Oct 1809 Assistant Surgeon 60th (Royal American) Regiment of Foot.
28 Jan 1811 Assistant Surgeon 4th Garrison Battalion.
5 Sept 1811 Assistant Surgeon 93rd (Highlanders) Regiment of Foot.<
5 Dec 1811 Assistant Surgeon Royal Wagon Train.
26 May 1816 Surgeon 31st (Huntingdonshire) Regiment of Foot.
8 Dec 1816 Surgeon 60th (Royal American) Regiment of Foot.
20 Nov 1817 Surgeon York Light Infantry Volunteers.
1817 Found guilty when tried by Court Martial, and lost two years seniority.
17 June 1824 Surgeon 99th (Lanarkshire) Regiment of Foot.
21 Sept 1830 Surgeon 7th (The Queen's Own) Hussars vice Surgeon William Dyer Thomas promoted Deputy Inspector General 22 July 1830.
12 Aug 1834 Exchanged with Surgeon Rhynd Lawder 59th (2nd Nottinghamshire) Regiment. On duty with the Service Companies since 18 Oct 1834.
Malta 1836 Surgeon 59th Foot.
Malta 15 Dec 1837 Surgeon 59th Foot. War Office Memorandum: "Surgeon John Gray Hibbert, 59th Foot has been restored to his original rank in the Army, viz 26 May 1814".
Malta 9 Apr 1838 Absent on leave till 8 Jan 1839.
Malta 8 Jan 1839 Returned from leave.
26 Jan 1841 Retired to half-pay. The vacancy in 59th Foot was filled by the promotion of Assistant Surgeon Thomas Williams 19th Foot.