(a) Timing of payments
The Attorney General shall pay to each State or specifically ¹ qualified unit of local government that receives funds under section 10404 of this title that has submitted an application under this subchapter the amount awarded to such State or unit of local government not later than the later of—

(1) the date that is 180 days after the date that the amount is available; or

(2) the first day of the payment period if the State has provided the Attorney General with the assurances required by subsection (c).

(b) Repayment of unexpended amounts

(1) Repayment required
From amounts awarded under this subchapter, a State or specially qualified unit shall repay to the Attorney General, before the expiration of the 36-month period beginning on the date of the award, any amount that is not expended by such State or unit.

(2) Extension
The Attorney General may adopt policies and procedures providing for a one-time extension, by not more than 12 months, of the period referred to in paragraph (1).

(3) Penalty for failure to repay
If the amount required to be repaid is not repaid, the Attorney General shall reduce payment in future payment periods accordingly.

(4) Deposit of amounts repaid
Amounts received by the Attorney General as repayments under this subsection shall be deposited in a designated fund for future payments to States and specially qualified units.

(c) Administrative costs
A State or unit of local government that receives funds under this subchapter may use not more than 5 percent of such funds to pay for administrative costs.

(d) Nonsupplanting requirement
Funds made available under this subchapter to States and units of local government shall not be used to supplant State or local funds as the case may be, but shall be used to increase the amount of funds that would, in the absence of funds made available under this subchapter, be made available from State or local sources, as the case may be.

(e) Matching funds

(1) In general
The Federal share of a grant received under this subchapter may not exceed 90 percent of the total program costs.

(2) Construction of facilities
Notwithstanding paragraph (1), with respect to the cost of constructing juvenile detention or correctional facilities, the Federal share of a grant received under this subchapter may not exceed 50 percent of approved cost.