Prices are difficult to find out in advance and impossible for anyone to explain after the fact. Patients who call providers to inquire about cost are told that information is proprietary or that they should check with the insurance company. Insurers also struggle to give exact numbers, since the amount you owe will depend on what exactly the provider bills for, how much of your plan’s deductible you’ve already paid and whether there are other cost-sharing terms in your plan. Online price estimator tools can sometimes give a ballpark, but even when people use these, they can end up with a bill that’s out of the stadium. That’s what happened to Michelle Smith, of Springfield, Pa: She used her insurer’s price tool to find a low-cost, in-network breast MRI provider and got an estimate of less than $1,375. Her bill was $3,237. Rubina Tahir, a chiropractor in Philadelphia, tried to price out how much the care she received during her pregnancy would cost, but even as a medical professional accustomed to dealing with insurance companies, she had trouble. She soared past her plan’s $2,000 deductible and hit the $5,000 out-of-pocket maximum when her daughter was born.