MEDIUM- AND LONG-TERM DEBT

Medium- and long-term debt is summarized as follows:



(in millions)	September 30, 2018		December 31, 2017
Parent company
Subordinated notes:
3.80% subordinated notes due 2026 (a)	$	243	$	255
Medium-term notes:
2.125% notes due 2019 (a)	347		347
3.70% notes due 2023 (a)	842		—
Total medium-term notes	1,189		347
Total parent company	1,432		602
Subsidiaries
Subordinated notes:
4.00% subordinated notes due 2025 (a)	332		347
7.875% subordinated notes due 2026 (a)	195		208
Total subordinated notes	527		555
Medium-term notes:
2.50% notes due 2020 (a)	659		665
Federal Home Loan Bank (FHLB) advances:
Floating-rate based on FHLB auction rate due 2026	2,800		2,800
Floating-rate based on FHLB auction rate due 2028	1,000		—
Total FHLB advances	3,800		2,800
Total subsidiaries	4,986		4,020
Total medium- and long-term debt	$	6,418	$	4,622


(a)	The fixed interest rates on these notes have been swapped to a variable rate and designated in a hedging relationship. Accordingly, carrying value has been adjusted to reflect the change in the fair value of the debt as a result of changes in the benchmark rate.

Subordinated notes with remaining maturities greater than one year qualify as Tier 2 capital.

Comerica Bank (the Bank), a wholly-owned subsidiary of the Corporation, is a member of the FHLB, which provides short- and long-term funding to its members through advances collateralized by real estate-related assets. In the first quarter 2018, the Bank borrowed an additional $1.0 billion of 10-year, floating-rate FHLB advances due January 26, 2028. The interest rate on the FHLB advances resets between four and eight weeks, based on the FHLB auction rate. At September 30, 2018, the weighted-average rate on the FHLB advances was 2.24%. Each note may be prepaid in full, without penalty, at each scheduled reset date. Borrowing capacity is contingent on the amount of collateral available to be pledged to the FHLB. At September 30, 2018, $15.9 billion of real estate-related loans were pledged to the FHLB as blanket collateral for current and potential future borrowings of approximately $5.2 billion.

On July 31, 2018, the Corporation issued $850 million of 3.70% senior notes maturing in 2023, swapped to a floating rate at 30-day LIBOR plus 80 basis points.

Unamortized debt issuance costs deducted from the carrying amount of medium- and long-term debt totaled $9 million at September 30, 2018 and $5 million at December 31, 2017.