There are many types of payroll costs that can be accounted for in an accounting system and that may have to be budgeted for by an analyst.  The following illustrates what these types of costs can be.

The list is not exhaustive, and will change with the organization in which the analyst works.  The analyst has to make adjustments to the payroll items of interest based on what is relevant and significant for his organization.   For example, if the organization is not responsible for a retirement trust fund, then the analyst does not have to budget for the trust fund costs.  Note that, although the listings are extensive, even OMB uses examples since it is not possible to define every possible item for a very large organization, such as the U.S. government.  Also note the need to pay attention to similar items that may be classified under a different category of expenditure.
This material is based on the 1999 OMB Circular A-11, where a more detailed listing can be found.  There are other sources for this type of information.  OMB uses the term "object classification" to identify cost categories, and assigns numerical codes to them.  There are major object classes and their subdivisions.  This listing preserves this classification.  (The numerical codes are the same ones that are used to present the budget; these codes are used mostly in the Appendix to the Budget of the United States.)  Major object classes (OC) are denoted by the first two digits; the decimal identifies the sub object class:
OC 11  Personnel Compensation.  Compensation directly related to duties performed for the Government by Federal civilian employees, military personnel, and non-Federal personnel

OC 11.1  For full-time civilian employees with permanent appointments.  Regular salaries and wages paid to the employees.   Other payments that become part of their basic pay (for example, geographic differentials, and critical position pay).  Regular salaries and wages paid while the employees are on paid leave, such as annual, sick, or compensatory leave.  Lump sum payments for annual leave upon separation.

OC 11.3  Other than full-time permanent.  Regular salaries and wages paid to civilian employees for part-time, temporary, or intermittent employment.

OC 11.5  Other personnel compensation.  Compensation above the basic rates paid directly to civilian employees.  Includes Overtime (which is pay for services in excess of the established work, standby duty and administratively uncontrollable overtime, and unscheduled availability duty hours for criminal investigations), Holiday pay, Night work differential (which is pay above the basic rate for regularly scheduled night work), Post differentials (above the basic rate for service at hardship posts abroad that are based upon conditions of environment substantially different from those in the continental United States and warrant additional pay as a recruitment and retention incentive), Hazardous duty pay (pay above the basic rate because of assignments involving performance of duties that subject the employee to hazards or physical hardships), Supervisory differential, Cash incentive awards, Other payments above basic rates, Royalties to Federal scientists and inventors

OC 11.7  Military personnel. The regular salaries and wages paid to military personnel.

OC 11.8  Special personal services payments.  Payments for personal services that don’t represent salaries or wages paid directly to Federal employees and military personnel. Include payments for:  Reimbursable details, that is, payments to other accounts for services of civilian employees and military personnel on reimbursable detail (both compensation and personnel benefits).  Reemployed annuitants, that is, payments by an agency employing an annuitant to reimburse the Civil service retirement and disability fund for the annuity paid to that employee.  Non-Federal civilians, such as witnesses; casual workers, patient and inmate help, and allowances for trainees and volunteers.  Salary equalization to individuals on leave of absence while employed by international organizations or State and local governments, when the equalization payment is 50 percent or less of the person’s salary.  Staff of former Presidents paid by GSA.

OC 12  Personnel Benefits.  Benefits for currently employed Federal civilian, military, and certain non-Federal personnel.

OC 12.1  Civilian personnel benefits.  Cash payments (from the agency, not funds withheld from employee compensation) to other funds for the benefit of Federal civilian employees or direct payments to these employees.  Also, payments to or for certain non-Federal employees as required by law.  Civilian personnel benefits include:  Insurance and annuities, which are the employer’s share of payments for life insurance, health insurance, employee retirement (including payments to finance fiduciary insurance costs of the Federal Retirement Thrift Investment Board), work injury disabilities or death and professional liability insurance.  Recruitment, retention, and other incentives, such as:  Payments above the basic rate for recruitment bonuses, relocation bonuses, and retention allowances; relocation and other expenses related to permanent change of station (PCS), except expenses for travel and transportation and the storage and care of vehicles and household goods; cash allowances for separate maintenance, education for dependents, transfers for employees stationed abroad, and personal allowances based upon assignment or position, and overseas differentials.  Other allowances and payments such as allowances for uniforms and quarters, special pay that is paid in a lump sum (such as compensatory damages or employee settlements), reimbursements for notary public expenses, and subsidies for commuting costs, that is, payments to subsidize the costs of Federal civilian employees in commuting by public transportation.

OC 12.2  Military personnel benefits.  Cash allowances and payments of employer share to other funds for military personnel. Include:  Cash allowances such as:  Uniform allowances; reenlistment bonuses; cost-of-living allowances; dislocation and family separation allowances; personal allowances based upon assignment or rank.  Exclude hazardous duty pay, flight pay, extra pay based upon conditions of work environment, and other such pay, which are classified as military personnel compensation in object class 11.7, and benefit payments to veterans resulting from their past service, which are classified as benefits to former personnel in object class 13.0.   Payments to other funds, such as the employer’s share of military retirement, Federal Insurance Contribution Act taxes, Servicemen's Group Life Insurance premiums, and education benefits.  Subsidies for commuting costs, which are payments to subsidize the costs of military personnel in commuting by public transportation.

OC 13  Benefits for former personnel.  Benefits for former officers and employees or their survivors that are based (at least in part) on the length of service to the Federal Government. Include:  Retirement benefits in the form of pensions, annuities, or other retirement benefits paid to former military and certain civilian Government personnel or to their survivors, exclusive of payments from retirement trust funds, which are classified as insurance claims and indemnities under object class 42.0.  Separation pay, which are severance payments to former employees who were involuntarily separated through no fault of their own and voluntary separation incentive (VSI) payments, also known as "early-outs" to employees who voluntarily separate from Federal service.  Payments to other funds for ex-Federal employees and ex-service personnel (e.g., agency payments to the unemployment trust fund for ex-employees and one-time agency payments of final basic pay to the civil service retirement fund for employees who took the early-out under buy-out authority) and other benefits paid directly to the beneficiary. Also, Government payment to the Employees health benefits fund for annuitants.  Exclude benefits provided in-kind, such as hospital and medical care, which are classified under the object class representing the nature of the items purchased