Healthcare is on its way to becoming a one-word noun throughout the English-speaking world. The change is well underway in British publications, where healthcare already appears about three times as often as health care and is used as both a noun and an adjective. Many American and Canadian publications resist the change, meanwhile, and health care remains the more common form in North American newswriting, as well as in government and scholarly texts. In many cases—such as on health-related U.S. government websites—health care is the noun (e.g., “your health care is important”) and healthcare is the adjective (e.g., “find a healthcare professional”), but this is not consistently borne out, and both forms are widely used both ways. Many publications and websites seem to have no policy on this at all.
Short answer: Outside North America (Australia goes along with the U.K. on this one), use healthcare. In the U.S. and Canada, make it two words (unless you want to help speed the compounding process).
U.S. and Canada
The health care law invests in training and supporting thousands of new primary care doctors and nurses by providing bonus payments, scholarships and loan repayment. [Healthcare.gov]
[T]hey demonstrate that health care reform is still an unpredictable work in progress. [Fortune]
Circumcision can also be a matter of family tradition, personal hygiene or preventive health care. [Mayo Clinic website]
You want to be a patient of the health care system, not a victim of it. [Globe and Mail]
The health care home model contributes to these goals by improving health care delivery at the patient level through redesigning and expanding the scope of primary health care services. [American Journal of Public Health1]
Make far greater use of society in healthcare. [Guardian]
The most important development in state intervention in healthcare provision in the pre-NHS period was the enactment of public health legislation. [Social Policy and Welfare]
It could adopt the healthcare reforms he was demanding before the election. [Telegraph]
NHS continuing healthcare is a package of continuing care provided outside hospital, arranged and funded solely by the NHS, for people with ongoing healthcare needs. [U.K. NHS website]
The setting up of public-private healthcare partnerships to take over provision of healthcare to the expatriate population is a near-term target. [Financial Times]
1. Grant, Roy, and Danielle Greene. 2012. “The Health Care Home Model: Primary Health Care Meeting Public Health Goals.”American Journal Of Public Health 102, no. 6: 1096-1103. ↩