A utility’s authorized rate of return is the profit percentage a state or federal regulator allows a monopoly utility to earn on the money it has invested in poles, pipes, plants, and other infrastructure serving customers. For the equity portion, the national average has been running around 9.7% as of early 2026. Because an electric, gas, or water utility usually faces no competition in its service territory, regulators set this percentage as a substitute for the price discipline a competitive market would otherwise impose, aiming to keep bills from reflecting monopoly pricing while leaving the company healthy enough to borrow, build, and maintain its system.
How the Percentage Turns Into Dollars on Your Bill
The percentage by itself tells you nothing. It only produces a number when it’s multiplied by the rate base, which is the dollar value of utility infrastructure that regulators have deemed eligible to earn a return. The rate base covers physical assets currently in service (power plants, transmission lines, water mains, treatment facilities) minus accumulated depreciation as those assets age.
The arithmetic is simple. A 7% return on a $2 billion rate base produces $140 million in authorized profit. That figure gets added to the utility’s operating expenses and taxes to arrive at the total revenue it’s allowed to collect from customers. Every residential, commercial, and industrial bill in the service territory is designed, in aggregate, to generate that revenue.
The Used-and-Useful Test
Not every dollar a utility spends makes it into the rate base. Regulators apply a “used and useful” standard that keeps assets out until they are in service and actually providing benefit to customers. A half-built power plant or excess capacity sitting idle can be excluded. The U.S. Supreme Court confirmed in 1989 that states can disallow recovery of capital investments that are not used and useful in service to the public without violating constitutional takings protections.1Legal Information Institute. Duquesne Light Co. v. Barasch, 488 U.S. 299 (1989)
Prudence Reviews
Even an asset that’s clearly in service can be challenged. In a prudence review, the commission asks whether the utility’s decision to make that investment was reasonable at the time. If the project was poorly planned, unnecessarily expensive, or reflected mismanagement, the commission can disallow some or all of the cost from the rate base. Shareholders absorb the loss instead of ratepayers. Historical disallowances have hit abandoned nuclear plants, experimental facilities, and costs tied to construction delays.
The two tests do different work. Used-and-useful asks whether the asset is serving customers now. Prudence asks whether building it was a reasonable call back when the utility committed the money. An asset can pass one and fail the other.
How the Rate Itself Is Built
The authorized rate of return is a weighted average of what the utility pays for its two kinds of financing: borrowed money (debt) and investor money (equity). Each source is multiplied by its share of total financing and its cost, and the results are added. The industry name for this calculation is the weighted average cost of capital.2National Association of Regulatory Utility Commissioners. Cost of Capital and Capital Markets: A Primer for Utility Regulators
Debt
Debt is the easy piece. When a utility issues bonds or takes out bank loans, the interest rate is in the loan agreement. If a utility has $500 million in long-term bonds at an average 4.5%, that’s its embedded cost of debt. Regulators verify the number against financial records, and there’s usually little fight.
Equity
The return on equity is where rate cases get contentious. Equity has no contract setting its price. Regulators have to estimate what shareholders need to justify holding the utility’s stock instead of putting their money somewhere else. Commissions rely on financial models to make the estimate, most often the discounted cash flow approach, which projects future dividend growth to infer the return investors expect, and the capital asset pricing model, which measures the utility’s risk against the broader market and adds a premium to a baseline return.
The models frequently produce different answers. Expert witnesses for the utility and for consumer advocates argue for competing inputs. A half-point difference may sound small, but on a multibillion-dollar rate base it translates into tens of millions of dollars a year. Recent authorized returns on equity for electric utilities have clustered around 9.7%, with individual decisions ranging from below 9% to above 10% depending on the utility’s risk profile and the commission’s judgment.
Capital Structure
The final weighted number depends on the mix. A utility financed 50/50 with debt at 4.5% and equity at 9.7% produces an overall return of roughly 7.1%. A heavier equity ratio pushes the overall return up, since equity costs more than debt. Some commissions use the utility’s actual capital structure. Others impose a hypothetical structure they consider more efficient, particularly when the utility carries an unusually high equity share that would inflate the bill.
Who Sets the Rate
Two layers of government regulate utility returns, and the dividing line is wholesale versus retail. The Federal Energy Regulatory Commission has authority over transmission of electric energy in interstate commerce and sales for resale, with jurisdiction that extends only to matters not subject to state regulation.3Office of the Law Revision Counsel. 16 USC 824 – Declaration of Policy; Application of Subchapter FERC does not reach local distribution facilities or purely intrastate transmission.
Your monthly bill is a retail transaction, and the return baked into it is set by your state public utility or public service commission. The same utility company may carry one FERC-approved return on its transmission assets and a separate state-approved return on its distribution network. The state proceedings are where most consumer advocacy happens, because that is where residential rates are decided.
How a Rate Case Gets Decided
The authorized rate of return doesn’t drift on its own. The utility has to file a formal rate case, and what follows looks more like a trial than a routine filing.
The utility compiles its financials around a test year, a consecutive twelve-month period meant to represent typical operating conditions.4National Association of Regulatory Utility Commissioners. Accounting in the Rate Case Process Some commissions use a historical test year drawn from actual past data. Others allow a forecasted year projecting expected costs and revenues. The choice matters: a historical year can leave the utility behind on costs that have risen since the data was collected, while a forecasted year gives credit for expenses not yet incurred.
After filing comes discovery, in which commission staff and intervenors (consumer advocates, large industrial customers, environmental groups) send detailed questions to the utility and get sworn answers. Staff often files its own independent analysis of what the return should be. Evidentiary hearings follow, usually in front of an administrative law judge, with witnesses testifying under oath and facing cross-examination. The commission then issues a written order setting the approved return and explaining its reasoning. Start to finish, a rate case runs anywhere from about six months to well over a year.
How You Can Participate
Rate cases are not closed proceedings. Most commissions hold public comment sessions where residential customers can speak about proposed increases without any legal representation. Those sessions are designed for ordinary ratepayers.
For deeper involvement, most states let individuals and organizations file as formal intervenors. Intervenor status gives you the right to issue discovery requests, file expert testimony, cross-examine the utility’s witnesses, and join settlement talks. The procedure typically starts with a written petition explaining your interest in the case and showing that the outcome will substantially affect you.
Cost is a real barrier. Attorneys and expert witnesses are expensive. A handful of states run intervenor compensation programs that reimburse advocacy groups for reasonable participation costs when their work helps the commission reach a better result. Where those programs exist, environmental organizations, low-income advocates, and community groups have been able to match utility experts in contested proceedings. Most states offer no such funding.
What Keeps the Utility From Over-Earning or Overspending
Setting the authorized return is only part of the system. Regulators also watch what the utility actually earns and how it chooses to spend.
Earnings Sharing
Some commissions build in an earnings sharing arrangement that triggers when actual results drift from the authorized return. If the utility earns well above its allowed return, a portion of the excess goes back to customers through bill credits or future rate reductions. The design usually includes a deadband, a neutral zone around the target where no sharing occurs, so normal fluctuations don’t trigger the mechanism. Beyond the band, the split between shareholders and ratepayers is often 50/50, though exact ratios vary. In some states the mechanism runs both ways, letting the utility collect a modest surcharge if earnings fall well below target.
The Capital-Bias Problem
Traditional rate-of-return regulation has a structural flaw. Because allowed profit is a percentage of the rate base, the utility has a financial reason to spend as much as possible on capital projects. Every new substation or pipeline enlarges the base it earns on. Economists call this the capital bias, and it can push utilities toward expensive infrastructure even when a cheaper operational fix would serve customers just as well.
Energy efficiency sits in the same trap. Under traditional ratemaking, a utility that successfully helps its customers use less energy also cuts its own revenue. Promoting conservation works directly against the bottom line.
Decoupling
Revenue decoupling breaks the link between what the utility collects and how much energy it sells. The commission sets an authorized revenue level, and if sales come in above or below the forecast, the gap is trued up through a balancing account. Overcollections flow back to ratepayers; undercollections get recovered. The utility ends up indifferent to sales volume, which removes the financial penalty for helping customers cut usage.5Lawrence Berkeley National Laboratory. The Theory and Practice of Decoupling Utility Revenues from Sales
Performance-Based Regulation
Performance-based regulation ties part of the utility’s earnings to measurable outcomes rather than just the size of its investment. Metrics cover reliability, environmental goals, customer satisfaction, and integration of renewable energy. Hit the targets and the utility earns a bonus; miss them and it pays a penalty. Many states pair these mechanisms with multiyear rate plans that lock in revenue for three to five years at a time, giving utilities room to cut costs between cases and keep part of the savings.
Neither decoupling nor performance-based regulation gets rid of the authorized rate of return. They sit on top of it, pulling utility behavior away from the spend-more-earn-more pattern and toward outcomes that reach the people paying the bills.