America’s transmission grid is under pressure. Electricity demand is climbing. Clean energy targets are multiplying. Planning systems—old and fragmented—aren’t keeping up. This report confronts that issue. It maps out how U.S. transmission planning works today, what’s broken, and what needs to change. At its core, the guide focuses on the Federal Energy Regulatory Commission (FERC). FERC’s orders shape everything: who plans, how they do it, who pays, and what gets built. Recent orders like 2023, 1920, and 1920-A push the system to plan longer, coordinate better, and factor in the broader value of transmission—resilience, cost savings, policy goals, and more. Each order addresses a piece of the puzzle: interconnection backlogs, cost allocation fights, or permitting bottlenecks. The report explains how RTOs and ISOs manage markets and grid balance in regions that use them—while other areas lag behind in efficiency and transparency. Areas without RTOs lag behind in grid modernization and in managing stress events like extreme weather. Several sections of this guide explore planning practices. These include economic modeling tools like cost-benefit ratios, congestion cost analysis, and levelized cost of electricity. Such tools guide decisions on whether to build, upgrade, or rethink projects. They also help weigh the long-term benefits—economic, environmental, and social—against upfront cost. Interregional transmission gets special attention. Connecting distant regions with high-voltage lines can reduce energy costs, increase reliability, and make better use of renewables. But these projects face steep hurdles. Siting takes years. Cost-sharing stirs political fights. Yet the upside is hard to ignore. Studies show billions in savings and stronger resilience if done right. The guide also covers stakeholder dynamics. Utilities, regulators, developers, and communities all have skin in the game. Friction is common, especially when timelines stretch and incentives clash. Still, coordination is essential. Recent rules push for stronger engagement—especially from states. Giving them more say could smooth approvals and reduce litigation. Looking ahead, the report also identifies new opportunities, such as grid-enabling technologies, evolutions in energy storage, and smarter permitting processes. The report also discusses recent legislation such as the BIG WIRES Act, which will encourage more regional coordination and buildout. Transmission planning in the U.S. requires a collaborative strategy. This report highlights three key factors: modeling tools, alignment between federal and state authorities, and the assessment of multi-value projects. Together, these can transform the current grid limitations into future infrastructure opportunities.