An agency must request VERA and receive approval from the Office of Personnel Management (OPM) before the agency may offer early retirement to its employees. Early Age Retirement.If your age plus your years of eligible service credit equal 80, you can retire under the "Rule of. 80. Bexar County offers employees a competitive salary, retirement, and benefits. Remember, to be eligible to retire your TMRS account, you need to have five (5) years of service at age 60 or 20 years of service at any age. Call the Texas Municipal Retirement System or TMRS at 1.800. 924.8677 to request your personalized retirement estimate. If you do not complete and return the Form W-4P, the. Employees Retirement System of Texas Chapter 61. It is intended to provide a structured framework and guidelines for staff to follow over the next two years.