Revenue to the fund consists of transfers from General Revenue Fund 0001 of:

1. At least one-half of an amount equal to 75 percent of oil production and natural gas production tax revenues in any fiscal year that exceeds fiscal 1987 collections.
2. One-half of any unencumbered General Revenue surplus at the end of each biennium.

Fund may include any other money appropriated to the fund by the legislature. Fund may be used to eliminate temporary cash deficiency in Fund (0001). Legislature may appropriate the fund for any purpose if two-thirds vote of members present in each house is received.

The Constitution caps the maximum balance at an amount not to exceed 10% of GR deposited during the previous biennium excluding investment income, interest income and amounts borrowed from special funds.

Minimum balance is equal to 7% of certified General Revenue-related appropriations made for the fiscal biennium. The balance may be invested by the Comptroller with 1/4 of the balance invested in a manner that ensures liquidity.

Prior to November 2014, Fund 0599 received the entire amount transferred from GR that was equal to 75% of excess oil and gas revenues above the 1987 level. H.B. 1 and S.J.R. 1, 83rd Leg., 3rd C.S. split the 75% transfer to deposit at least one-half to Fund 0599 and the remainder to the State Highway Fund 0006. This was approved by the voters in November 2014.

H.B. 1, 83rd Leg., 3rd C.S. added provision for determining Fund 0599 sufficient balance by legislative committee.

H.B. 903, 84th Leg., R.S. added investment of amounts above minimum balance.

S.B. 69, 86th Leg., R.S. changed minimum balance to 7% calculation and amended the Comptroller's investment authority.