"However, solutions that will provide more seamless coverage and ease transitions exist, and some solutions simply require extending and improving existing policies."
The group suggested that state and federal officials align and simplify eligibility and application rules across Medicare, Medicaid and the insurance exchanges.
Regulators should also pursue data-sharing arrangements that would easily verify seniors' eligibility for Medicare, and launch outreach plans to educate consumers about the transition process, the report urged.
"By taking these steps now," said Medicare Rights Center President Joe Baker in a statement, "state and federal governments can help ensure that people who become eligible for Medicare are protected from gaps in coverage and unnecessary out-of-pocket costs that could put their health and economic security at risk."
The report said its reforms would benefit three groups: seniors moving from exchanges' qualified health plans into Medicare, seniors moving from Medicaid into Medicare and those who eligible for both Medicaid and Medicare.
Officials face an enormous task in creating the technical infrastructure to support the healthcare law's insurance exchanges and its Medicaid enrollment as some states expand that program.
Every state must have an exchange by Jan. 1, 2014.
Read more from Monday's report here.