WASHINGTON — Seven months after Maine voters approved a ballot measure to expand Medicaid to tens of thousands of additional residents, a state judge on Monday ordered Gov. Paul LePage’s administration to stop stonewalling and move ahead with the plan.

It was the second victory in a week for Medicaid expansion, which became possible under the Affordable Care Act. Lawmakers in Virginia voted last week to open the program to an additional 400,000 residents. Advocates in Utah have succeeded in getting a question on the November ballot about expanding Medicaid, and similar efforts are underway in Idaho and Nebraska.

In Maine, Medicaid expansion advocates sued the LePage administration in April after it missed the deadline for submitting a plan to the federal government to expand the program. Residents who are newly eligible for Medicaid as a result of the ballot measure were supposed to get coverage starting in July, but Mr. LePage, a Republican, has repeatedly said the state doesn’t have the money to pay for it.

Maine was the first state in the nation to expand Medicaid through a public referendum. Governors and legislatures in 17 other states that have refused to expand Medicaid under the Affordable Care Act are watching closely.