01 / Occupational profile
Your 91A occupational profile
Turbine engine and shop tool noise
Common occupational factor
The Abrams' gas-turbine engine, auxiliary power unit, and motor-pool power tools create sustained high noise levels during diagnosis and testing.
Confined-space work and heavy component handling
Common occupational factor
Reaching into turret and hull compartments, working in awkward postures, and handling heavy suspension and hydraulic components load the back, shoulders, and knees.
Hydraulic fluid, fuel, and NBC-system contact
Common occupational factor
Servicing hydraulic systems, the auxiliary power unit, and the gas-particulate system involves repeated skin and inhalation contact with hydraulic fluid, fuel, and filtration-system materials.
Outdoor field maintenance and range support
Common occupational factor
Gunnery range support and field maintenance occur outdoors in all weather, including extended desert deployments.
02 / Your service
What did you actually do?
Your MOS is the starting point. Your actual assignment, era, equipment, location, and duties determine which parts of the occupational history are relevant. Use the Evidence Builder below to select your actual duties and see records that may corroborate them.
91As diagnose and troubleshoot malfunctions using electronic, electrical, and mechanical test equipment, schematics, and wiring diagrams. Organizational and direct-support maintenance tasks include the suspension system, steering system, hydraulic system, auxiliary power unit, fire-extinguisher/suppression system, and gas-particulate (NBC protection) system, along with the vehicle-mounted armament, gun-turret drive system, and fire-control system. Work happens in motor pool bays and in the field, often reaching into confined turret and hull spaces, running the auxiliary power unit and turbine engine for diagnosis, and handling hydraulic fluid and ballistic-shield components during repairs.
Duties that may vary by assignment
- Diagnosing and troubleshooting Abrams electrical and mechanical systems with test equipment
- Maintaining suspension, steering, and hydraulic systems
- Servicing the auxiliary power unit and fire-extinguisher/suppression system
- Maintaining the gas-particulate (NBC protection) system
- Organizational-level maintenance on vehicular armament, turret drive, and fire-control systems
- Working in confined turret and hull spaces
- Hydraulic fluid and fuel handling during repairs
- Field maintenance in dust, heat, and cold
Private, on this page only
Military Occupational Evidence Builder
Based on what you actually did in the military, what records might document it? Select only what applied to you. No name, file number, contact details, free text, or upload. Nothing is saved or sent.
Military service
Army · 91A M1 Abrams Tank System Maintainer
For another specialty, open its guide from the MOS library. A job code alone does not establish individual duties or exposure.
Era(s) of service
Deployments
Already have a VA decision?
Your Evidence Builder identifies records that may document your service history. If VA has already decided your claim, the next question is different: what did VA accept, what did VA reject, and why?
Request a free decision review03 / Corroboration
Building your occupational history
Records matter because they can connect a job title to an individual's actual work and circumstances.
Turbine engine and shop tool noise
Records that may corroborate it
- · Hearing-conservation audiograms (DD 2215/2216) and DOEHRS-HC records
- · Assignment records placing you in an armor maintenance unit
- · Evaluations describing maintenance-bay or field duties
Limit: Documented noise supports the in-service event only. A current hearing disability under 38 CFR § 3.385 or a tinnitus complaint, and a medical link, are still required.
Confined-space work and heavy component handling
Records that may corroborate it
- · Sick call and physical therapy entries during the assignment
- · Line-of-duty or incident reports for a documented injury
- · Evaluations describing maintenance duties
Limit: Typical tank-maintenance demands do not by themselves establish that a specific joint was injured in service; a current diagnosis and medical opinion are required.
Hydraulic fluid, fuel, and NBC-system contact
Records that may corroborate it
- · Occupational health or hazmat-program records, if enrolled
- · Evaluations describing maintenance duties
- · Unit safety or environmental records for the motor pool
Limit: The MOS does not establish contact with any specific product or exposure level. Era, tasks, a current diagnosis, and a medical opinion all still matter.
Outdoor field maintenance and range support
Records that may corroborate it
- · Deployment orders and unit location records
- · Sick call entries for heat or cold injury
- · Evaluations describing field or range-support duties
Limit: Outdoor work alone does not establish a specific heat, cold, or skin-injury diagnosis; clinical findings and a medical link are required.
04 / Evidence standard
What your MOS can — and cannot — establish
May help document
Work performed, circumstances of service, consistency of an alleged exposure, and the nature or duration of duties where supported by individual records.
Does not automatically establish
A diagnosis, medical causation, severity, percentage, presumption, or entitlement to service connection.
05 / Medical evidence
Conditions that may be relevant to the occupational history
This is not a list of conditions to claim. A veteran's actual diagnosis and individual service record determine relevance; occupational evidence is not medical causation.
Hearing +
Tinnitus and hearing loss
Why the occupation may matter: Turbine engine testing and shop tool noise are sustained features of Abrams maintenance.
Records and clinical evidence: Audiometry meeting 38 CFR § 3.385, service audiograms, and a medical opinion.
Occupational history alone does not establish this diagnosis or its medical relationship to service.
Spine / joints +
Back, shoulder, and knee conditions
Why the occupation may matter: Confined-space work and heavy component handling load the back and joints repeatedly.
Records and clinical evidence: Current diagnosis, in-service treatment or duty records, and a medical opinion.
Occupational history alone does not establish this diagnosis or its medical relationship to service.
Skin +
Skin conditions from hydraulic fluid and fuel contact
Why the occupation may matter: Repeated skin contact with hydraulic fluid and fuel is part of routine maintenance tasks.
Records and clinical evidence: Current dermatology diagnosis, duty records, and a medical opinion.
Occupational history alone does not establish this diagnosis or its medical relationship to service.
06 / Exposure record
ILER and toxic exposure
For applicable exposure-related claims, VA may review the Individual Longitudinal Exposure Record (ILER) and a toxic exposure risk activity (TERA) memorandum along with deployment and occupational records. An ILER entry does not automatically establish exposure or service connection.
07 / After a decision
Why a 91A claim may still be denied
An exposure finding is not the same as a grant. These are examples from the researched guide, not predictions about a particular case.
VA may accept
A duty or event consistent with the service record
But may deny
A diagnosis, medical relationship, or rating element
Record to examine
Decision findings, service and private treatment records, examination rationale, and medical opinions.
Exposure described too generally
Statements like "I worked on tanks" without the system (hydraulic, APU, turret) and setting are hard for VA to evaluate; MOS school records and evaluations may add the specifics.
No in-service complaint for joint pain
Mechanics often worked through strains from confined-space work without a sick-call visit; buddy statements and duty records may help fill that gap.
Hearing claim rejected on a normal separation audiogram
A normal exit audiogram alone does not decide a hearing claim, but examiners sometimes rely on it without addressing the full in-service noise history.
Oakridge Claims / Appeals Focused
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The important question is what VA accepted, what it rejected, and why. A decision review considers the decision, examinations, and the complete record — including private and VA records that may need development. Oakridge is appeals-focused — core work is post-decision, but initial and new claims are accepted on a case-by-case basis (no fee for pre-decision work).
Fees for eligible post-decision representation are governed by a written agreement. See fee details. No outcome is guaranteed.
91A questions
Does my 91A MOS prove I worked on the fire-control or armament system?
It shows the occupational field includes organizational-level maintenance on those systems, but your specific duties depended on your unit and assignment. Evaluations describing your tasks may help clarify what you actually worked on.
What records show which Abrams systems I actually maintained?
MOS school and OJT certification records, unit assignment orders, and evaluations describing your duties are the usual starting points.
I never reported my back pain in service. Is there anything to look for?
Possibly. Evaluations, maintenance logs, and statements from soldiers you served with may help document the duty demands, though none of them guarantees an outcome.
Sources and legal references
General education only; not legal or medical advice. Oakridge Claims is a private business, not affiliated with or endorsed by VA. Nothing here establishes a representative-client relationship or guarantees a result. Free accredited VSO help is available.