Items are placed in box 14 by your employer to provide you with additional information about various components of your pay.
The IRC 125 probably refers to pre-tax contributions you made to your employer's plan for dependent child care reimbursement plan or a medical reimbursement plan or both. This information may be necessary for the preparation of your tax return. Any child care paid for out of this account may not be used to claim a dependent child care credit. Likewise, medical expenses paid out of a 125 account may not be deducted on Schedule A.
The IRC 414h refers to amounts contributed to your pension plan, 457 plan, 401(k) or 403(b) plan by your employer as being designated "employee contributions". These amounts may refer to nonelective employer contributions made on your behalf; after-tax contributions made by you; required employee contributions made by you and/or employer matching contributions. These amounts are for your information only and do not require any entries on your part in your tax return.
For more information I suggest you contact your human resources department for a further explanation.
It would be helpful if based on my previous answer you could give me your best guess as to what the amounts represent. Did you contribute to a 125 plan (you may have also heard the term cafeteria plan) for dependent child care reimbursement or medical reimbursement? Do you participate in a retirement plan (what type) in which your employer makes contributions for you?
If the items are taxable they would also be included in box 1 of your W-2.
With respect to the IRC 125 such contributions are generally made on a pre-tax basis. You withdraw the funds when you apply to the plan administrator for reimbursement. To the extent you use the funds for the intended purpose, they will not be taxable. Likewise, if you pay for tax deductible expenses with these pre-tax dollars, you may not take the deduction for the amount reimbursed.
The IRC 414h item will generally not be taxable until you withdraw it from your pension plan.