Although the doctor was fully vaccinated and wore a mask during the visits, Newmarch House in Caddens, near Penrith, has quickly locked down in a bid to limit potential infections.
The doctor also visited SummitCare Penrith and Mountainview Penrith.
Newmarch House was one of two major clusters in aged care facilities last year, along with an outbreak at the Dorothy Henderson Lodge in Macquarie Park.
A spokesperson for the Nepean Blue Mountains Local Health District noted the Federal Government is responsible for both the aged care sector and the national rollout of the COVID-19 vaccination program.
So far, no residents or staff have been infected with the virus and the majority of those living and working at the Anglicare-owned centre have been vaccinated.
At SummitCare Penrith, 85 per cent of the 85 residents and 87 per cent of healthcare staff are double-dose vaccinated.
At Newmarch House, 90 per cent of the 94 residents and 97 per cent of healthcare staff are fully vaccinated, while at Mountainview Penrith, 93 per cent of the 88 residents and 96 per cent of staff have received two jabs.
All affected residents and staff across the facilities are being tested, with residents being monitored closely by doctors, nurses and specialists for symptoms.
The facilities have notified the families of residents.
"During a COVID-19 outbreak in an aged care facility, an Outbreak Management Team OMT) meets at least daily to ensure appropriate safety, care and support is provided," the spokesperson said.
Newmarch House was the centre of a major COVID-19 outbreak last year, with 19 residents dying.
A total of 37 residents and 34 staff were infected.
The outbreak was one of the deadliest periods of the COVID-19 pandemic seen in Australia.
On June 15 last year, NSW Health declared that outbreak — believed to have been sparked by an infected staff member who worked multiple times with extremely mild symptoms — over.
The response from Anglicare and government bodies has since been harshly criticised after new infections continued to appear more than two weeks into a full lockdown of the home.