The programs at stake are worth billions of dollars and affect millions of people, both in the U.S. and abroad. Here are some of the key initiatives on the congressional agenda:

The Medicaid Disproportionate Share Hospital program, which provides funding to hospitals that treat large numbers of people who can't pay for care, faces an $8 billion cut this year and each of the next three years.
Legislation to reauthorize and fund community health centers, the National Health Service Corps and teaching hospitals that run graduate medical education programs, which all need to be renewed.
The Pandemic and All-Hazards Preparedness Act of 2006, which aims to help the U.S. detect and counter infectious disease outbreaks such as COVID-19 or biological attacks.
The SUPPORT for Patients and Communities Act of 2018, which funds treatment and education programs to combat the opioid epidemic.
The President’s Emergency Plan for AIDS Relief, or PEPFAR, which debuted under President George W. Bush and is credited with saving 25 million lives.

Cassidy is hardly the only frustrated lawmaker. Even though most of these programs enjoy strong bipartisan support, unrelated issues are complicating prospects for collaborative action.

The most significant snags are emerging from the House, where many of the more conservative Republicans have signaled they will not pass government funding—which also expires on Sept. 30—even though many voted for the spending levels that House Speaker Kevin McCarthy (R-Calif.) agreed to last spring when Congress raised the debt limit. Then there's McCarthy's announcement Tuesday that House is launching an impeachment investigation against President Joe Biden.

"If these crazy House Republicans weren't fighting with themselves over who cares about impeachment more, and instead were focused on keeping health clinics open, maybe we would be in less of a crisis," said Sen. Chris Murphy (D-Conn.), who sits on both the Appropriations and HELP committees.