NIPSCO's $1.64B TDSIC Overrun: What the Supreme Court Decision Means for Your Bills

On May 21, the Indiana Supreme Court heard arguments in IURC case 45557, NIPSCO's appeal over whether inflation-driven overruns on its $1.64 billion electric infrastructure plan can be recovered through the TDSIC tracker rather than a base rate case. The NIPSCO Industrial Group, a coalition of six major industrial customers including US Steel, argued that routing costs through the tracker bypasses the prudence review that protects customers from spending that isn't cost-justified. NIPSCO countered that transformer and breaker costs surged more than 150% and that a standard 70-foot wood pole went from roughly $3,000 in 2019 to more than $5,600 in 2024.

What the coverage is missing: NIPSCO's TDSIC 6 billing period covering April through September 2025 is already collecting costs while the court deliberates. A separate $741 million gas TDSIC plan is pending with OUCC testimony already filed. AES Indiana, CenterPoint, Duke, and Indiana Michigan Power are all watching, they operate under the same statute, so whatever standard the court sets applies across the board.