Can Walmart make $4 co

Wal-Mart has played it safe when it comes to retail clinics, partnering with regional hospitals to offer services like flu shots. But now, the retailer is taking a more aggressive tack, with in-store branded clinics offering primary care at a price competitors may find hard to match.

'It was important to Wal-Mart that we be able to maintain or be a price leader in this space,' said Jennifer LaPerre, Wal-Mart U.S. senior director for health and wellness, who is overseeing the rollout of the company's new Walmart Care Clinics.

LaPerre was in Carrollton, Georgia, in the foothills of the Appalachian mountains, to open the ninth Walmart Care Clinic. Three more are planned this year as part of a pilot program to offer primary care services such as health screenings and disease management of conditions like diabetes and high blood pressure in-store.

Read More New twists ahead for your employer's health plan

The price? Just $4 for employees and dependents on the company's health plan. For customers, the price is $40-about the same as an online telemedicine consultation with a doctor.

'We wanted to be able to monitor and manage and control price. We wanted to be able to focus on a scope of services that were meaningful to our customers and associates,' LaPerre said.

Wal-Mart is able to price it that low, in part because the clinics are staffed by nurse practitioners from Quadmed, a provider of on-site workplace clinics.

'These particular set of services that are going to be provided are really ideal for a nurse practitioner to manage,' said Dr. David Severance, corporate medical director for Quadmed, though each clinic is overseen by a supervising physician.

Read More Watch out retailers, Wal-Mart takes hit on health care

Severance said he expects the low price could make a big difference for patients with conditions like diabetes and hypertension, who need to get check-ups every three to six months.

'If a patient has a fairly sizable co-pay, just to see the provider for each one of those visits, there's a much greater likelihood that they won't follow through with what the prescribed treatment is,' he said.

Rx for employee health care

Offering its employees a visit with a nurse practioner for the price of a latte at Starbucks could also help Wal-Mart control its own health-care expenses. Earlier this month, the retailer revealed its health costs were expected to increase by $500 million this year because more of its workers than expected are signing up for its health-insurance benefits.

While Wal-Mart won't discuss possible reasons for the enrollment surge, the push for Obamacare enrollment likely played a role, according to Neil Trautwein, a vice president at the National Retail Federation. In states that opted out of Medicaid expansion, Wal-Mart workers may not have been able to get subsidies for health exchange plans. Under the Affordable Care Act, subsidies kick in for those making over $15,900 a year.

Read More Why your boss wants you to see online doctors

'To the extent that a state has not expanded Medicaid and the individual ... faces their own obligation to obtain coverage, then that may make an employer plan more attractive,' Trautwein said.

Wal-Mart is launching the clinic pilot program in three states that didn't expand Medicaid-Texas, South Carolina and Georgia-states that also have a high concentration of uninsured residents.

'With their in-store clinics, that's a pretty good way to handle that added enrollment and first-time health coverage consumers,' Trautwein said.

But it's just as important to Wal-Mart to leverage the clinics to drive overall sales.

'As we look at the business model ... it was not just about looking at the clinics in isolation,' LaPerre said. 'The traffic coming into the Walmart Care Clinic really benefits the entire box.'

Priced to disrupt

Consumer-directed health-care services represent a $235 billion market, according to the Advisory Board Company, a health-care research and consulting firm. Wal-Mart could become a big player through its clinics.

'I think there is the potential to make a real dent in the marketplace,' said Christopher Kerns, a managing director at the Advisory Board.

Kerns and his colleagues wrote about a big retailer planning to expand into primary care in a 2013 report titled The Consumer-Oriented Ambulatory Network. The retailer said when it came to referrals, it would partner with hospitals and doctors based on pricing and quality.

Read More Want to get pregnant? This Glow app can help

'Providers have a choice to make. They can either compete with many of these retail providers ... by offering lower-cost services that are not just cheaper, but they are also more convenient and of a higher service standard, ... or they can partner with them,' Kerns said.

Few providers could compete with Wal-Mart's $4 office visits for its associates, and it's not clear the retailer could ever make that price point work for its customers. So, why make it that cheap?

'The $4 price point was not magical. There wasn't a lot of science. For us, it was about being consistent,' LaPerre said. The company was the first to introduce $4 generic drugs at its pharmacies in 2006, prompting others to lower their pricing on generics.

'That has brand recognition, and candidly, was meaningful from an offering compared to the health-care industry,' she said.

Call it a $4 wake up call to providers: Wal-Mart is getting serious about health care.

-By CNBC's Bertha Coombs