The Air Force in fiscal 2019 will increase the maximum retention bonus airmen can get for re-enlisting to $100,000 as part of a major expansion of the program.

The bonus was previously capped at $90,000, although not all airmen eligible for a selective re-enlistment bonus received the maximum amount.

The Air Force also plans to increase the number of career fields eligible for the bonuses to 115 in fiscal 2019, up from 92 in May, according to a chart that was posted on myPers and provided by Air Force Personnel Center. The unofficial Facebook page Air Force amn/nco/snco first posted images of the chart Thursday.

Eligibility for re-up bonuses regularly fluctuates in the Air Force, but it is one of the key ways the service seeks to encourage airmen in some of its most undermanned and critical career fields to stay. Encouraging retention is especially important now, as the Air Force seeks to continue its expansion after a painful drawdown four years ago. The Air Force expects to add 4,000 active duty airmen in fiscal 2019, which begins Monday, and 700 airmen in the Air National Guard and Air Force Reserve.

Earlier this month, service leaders unveiled an aggressive growth plan that they say is needed for the Air Force to carry out its responsibilities under the National Defense Strategy. That plan calls for a 24 percent increase in the number of operational squadrons by 2030, to 386, and a corresponding growth in personnel, which would see the addition of at least 40,000 more uniformed airmen and civilians.

The complete list of career fields eligible for SRBs

Nearly as many Air Force specialty codes will be eligible for the bonuses as there were in early 2016, when 117 jobs were eligible.

Special missions aviators in the 1A9X1 career field, who serve as gunners on AC-130 gunships, are among the 28 career fields that were added to the retention bonus list since May. Those airmen, who also serve as gunners and engineers on rescue helicopters in Air Combat Command, have frequently been stressed over the years with the pace of their deployments. Last month, ACC commander Gen. Mike Holmes said special missions aviators were one of his top manning concerns.

Aircraft loadmasters, airborne intelligence, surveillance and reconnaissance superintendents, air traffic controllers and remotely piloted aircraft sensor operators were also added to the list.

Several maintenance career fields were added, including 2A5X4D and 2A5X4F B-52 and B-2 bomber maintainers, as well as 2A9X3E and 2A9X3H bomber/special electronic warfare and radar surveillance integrated avionics airmen for the B-1 and EC-130 Compass Call, respectively.

Five career fields, such as 1A6X1 flight attendants, 4P0X1 pharmacists and 3F0X1 personnelists, were dropped from the previous list, meaning the total number of Air Force specialty codes on the list increased by 23 since May.

About 20 career fields that were already on the list, such as 1A0X1 in-flight refueling and 1A1X1 flight engineers, have seen increases to some of their zones, and about six other AFSCs saw decreases to some zones.