Okla. Admin. Code § 590:10-19-2
The following words or terms, when used in this Subchapter, shall have the following meaning, unless the context clearly indicates otherwise:
"Board" means the Board of Trustees for the Oklahoma Public Employees Retirement System.
"Eligible Member" means a member of the System who retires on or after the Option Effective Date and who is not Medicare-eligible at the time of retirement, except as otherwise provided in this Subchapter.
"Medicare Gap Benefit" means an adjusted retirement benefit which is greater than the member's Regular Retirement Benefit for months of payments prior to and including the month the member becomes Medicare-eligible and an actuarially reduced benefit which is less than the member's Regular Retirement Benefit for months of payments after becoming Medicare-eligible and for the remaining lifetime of the member.
"Medicare Gap Benefit Election" means an irrevocable election made by an Eligible Member prior to his or her effective date of retirement to receive the alternative benefit option payable pursuant to this Subchapter.
"Medicare-eligible" means age 65 or older, or such other age at which a member becomes eligible for Medicare benefits under federal law in effect at the time a member applies for an OPERS retirement benefit. For purposes of this Subchapter, age is calculated as of the first day of the month of birth. For example, a member born September 15, 1940, is considered to be 65 and Medicare-eligible on or after September 1, 2005.
"Minimum Medicare Gap Benefit" means a gross monthly benefit payment of $200.00 per month after all applicable actuarial reductions for either the Pre-Medicare benefit or the Post Medicare benefit.
"Option Effective Date" means May 1, 2006, which is the date when the System made the Medicare Gap Benefit option available to Eligible Members.
"Post Medicare Benefit" means the actuarially reduced monthly benefit payment for all months of retirement after the member becomes Medicare-eligible.
"Pre-Medicare Benefit" means the increased monthly benefit payment for all months of retirement prior to and including the month the member becomes Medicare-eligible.
"Pre-Medicare Increase" means the amount added to the Regular Retirement Benefit to equal the Pre-Medicare Benefit.
"Regular Retirement Benefit" means the monthly retirement benefit that the Eligible Member would receive absent the Medicare Gap Benefit Election, which includes the actuarial adjustments as a result of the member's election of early retirement and/or survivor benefit options. It does not include amounts refunded of additional contributions paid to a member in the form of a limited retirement benefit under 74 O.S. § 910.5.
"System" or "OPERS" means the Oklahoma Public Employees Retirement System.
Okla. Admin. Code § 590:10-19-2