WASHINGTON (MCT) — They are two of the largest parts of the federal government. They’re growing. And they’re heading toward financial problems that will touch tens of millions of Americans unless something changes.

Medicare is the nation’s biggest buyer of health care, spending $550 billion last year to provide care for 48.7 million Americans. The problem is that the taxes paid by workers and employers to finance the program aren’t covering the full cost, and the government since 2008 has been drawing off its trust fund to make up the difference. Barring changes, the trust fund runs out in 12 years — 2024 — and the government would have to raise taxes or cut services.