The financing economics were already known. The notes were priced on August 10 and scheduled to settle on August 24, so this filing lands as completion paperwork rather than a new financing surprise. The underwriting agreement is dated August 10, 2026 〔0〕.
MPLX is adding $2.25 billion of senior debt across three maturities. The published terms show $1.25 billion due 2029, plus $500 million due 2032 and $500 million due 2036, with net proceeds of approximately $2.216 billion.
| Tranche | Principal | Coupon | Maturity |
|---|---|---|---|
| Senior notes | $1.25B | 4.700% | 2029 |
| Senior notes | $0.50B | 5.000% | 2032 |
| Senior notes | $0.50B | 5.500% | 2036 |
The August 24 8-K mainly supplies the legal instruments. It files three supplemental indentures dated August 24, 2026 〔1〕 and does not add earnings, guidance, leverage targets or a new use-of-proceeds disclosure. Against a market that already knew the offering’s size and pricing, the net read is neutral.
Read the original 8-K on SEC EDGAR ↗