WASHINGTON — In a rare moment of bipartisanship, the Senate on Monday overwhelmingly passed a sweeping package of bills aimed at addressing the nation’s deadly opioid epidemic.

The vote was 99 to 1 with only Sen. Mike Lee, R-Utah, dissenting.

President Trump and Congress vowed a federal government response to a crisis that affects millions of Americans and was responsible for the deaths of close to 50,000 last year. Trump has declared the epidemic a public health emergency. It is one of the only major pieces of legislation that Congress is expected to pass this year as lawmakers gear up for the midterm elections in November.

The package of 70 Senate bills costs $8.4 billion and creates, expands and renews programs across multiple agencies. It’s ambitious in scope, aiming to prevent the deadly synthetic drug fentanyl from being shipped through the U.S. Postal Service as well as allowing doctors to prescribe more medication designed to wean addicts off opioids, such as buprenorphine.

“It doesn’t include everything all of us want to see but it has important new initiatives and it’s a step in the right direction,” said Sen. Rob Portman, R-Ohio, who has advocated several measures that are part of the package.

“Congress is committing itself to actually putting politics aside. It’s not just bipartisan – I think it’s nonpartisan.”

Yet many public health advocates and experts say it doesn’t offer the one thing truly needed: The massive amount of funding to fully combat a crisis that deeply affects rural and urban communities across America.

Sarah Wakeman, the medical director for Mass General Hospital’s Substance Use Disorders Initiative, said really targeting the depth of the opioid epidemic would require an infusion of federal dollars on par with the more than $20 billion a year spent on HIV/AIDs.

“We have historically not thought of addiction as a medical issue and so our health care and public health system are woefully unprepared to respond in a robust way,” she said.

The House passed a similar measure in June, and the two chambers will need to negotiate a few differences before sending the package to Trump’s desk.

The biggest difference between the House and Senate measures involves an obscure, decades-old rule known as the Institutions for Mental Diseases exclusion rule, or “IMD exclusion,” prohibiting federal Medicaid reimbursements for inpatient substance abuse treatment in centers with more than 16 beds whose patients are mainly suffering from severe mental illness. Many people with substance abuse disorders also have a mental illness, and this rule means they are unable to get treated for their addiction when in a large mental health facility. The House bill partially overturns the IMD exclusion for mental-health patients who have an opioid use disorder.