I often get questions about how a service member can access his or her MyPay account, particularly to view his or her Leave and Earnings Statement (LES). MyPay is the Department of Defense's online payroll and accounting system that allows a service member to view his or her pay account, view travel claims, make changes to withholding and allotments, and change Thrift Savings Plan (TSP) contributions.
First, you must access the MyPay website by going to http://mypay.dfas.mil.
Second, you must have your social security number or your MyPay Login ID. First time users may log in with their social security number and will then be required to create a Login ID.
Third, you will need to enter your Personal Identification Number (PIN). If you do not know your pin or have not received your PIN, you can click on the "Reset current or request new password" hyperlink. If you have an email address on file with MyPay, (which would be done through a previous MyPay visit, or through an "appropriate administrator." I don't know what that means, maybe your finance office?) your temporary new password may be emailed to you. Otherwise, it will be mailed via regular US mail to your address of record. If you suspect your address might be incorrect in the pay system, you will need to check with your finance office to update your address. Your finance office might also be able to help you with PIN issues.
There is a ton more information at the MyPay FAQ website.
I hope this helps!