More Americans have health insurance, but they’ve also become increasingly worried over the past two years about how to pay for every aspect of their medical care. While the majority of insured adults still can afford their health care, the minority who say it’s “difficult” to pay their monthly premiums, doctor and prescription copayments, and deductibles is growing. Potential explanations for these concerns, revealed in a new Henry J. Kaiser Family Foundation poll, include rapidly rising prescription drug costs and the fact that employer-provided health insurance plans with high deductibles are far more common than they used to be. To be sure, the Affordable Care Act (ACA) has expanded Americans’ access to health insurance, and federal subsidies have made t…