Athol Memorial Hospital made headlines recently when it was ranked one of the best hospitals in the country by The Joint Commission, a nonprofit hospital accreditation organization, joining five other Massachusetts institutions. "I think we showed that, along with a lot of other small hospitals in the country, that we do really good quality care," said Athol Memorial President and CEO Steve Penka. The 25-bed hospital intends to remain small, but not independent. It's in the process of being acquired by Vanguard Health Systems, the owner of Saint Vincent Hospital in Worcester and MetroWest Medical Center in Framingham and Natick. That will mean becoming a for-profit hospital, assuming the change meets with state approval. But Penka said the acquisition won't hamper its ability to provide excellent care. Athol Memorial announced its intention to join Vanguard in March 2010. Penka said the two parties are now working under a letter of intent —which is being kept private—and going through a due diligence process.