HARRISBURG — Gov. Tom Corbett was to start a three-day tour today to lay out his plans to improve health care and reveal the conditions under which he would accept additional Medicaid dollars under the sweeping federal health law designed to provide insurance to more working poor.

A key condition for Corbett will be an idea being explored by some other states — using the Medicaid dollars to buy private insurance policies instead of expanding government rolls — where Republicans are wary of expanding traditional Medicaid.

The announcement arrives after months of Corbett aides pressing the U.S. Department of Health and Human Services to accept the governor’s terms to join the Medicaid expansion, a major element of President Barack Obama’s signature 2010 law.

Corbett, a Republican who sued unsuccessfully to overturn the federal law, is a critic of Medicaid, saying it is bloated and costly, and his aides insist that the forthcoming proposal will not amount to an expansion of Medicaid’s enrollment.

“Gov. Corbett does not support growing an entitlement program as he has been very clear about the need for reform,” spokesman Lynn Lawson said Friday.

Three people who are familiar with the plan said Corbett’s conditions to accept the money reflect ideas that administration officials have publicly discussed in recent months.

For states that participate in the Medicaid expansion, the extra federal money becomes available Jan. 1.

However, it is not yet clear whether the U.S. Department of Health and Human Services will agree to Corbett’s conditions, and the Corbett administration has yet to submit an official request for approval. In addition, Corbett’s public welfare secretary, Beverly Mackereth, has said previously that the administration will probably need until 2015 to negotiate and prepare for a Medicaid expansion plan.

The conditions Corbett will lay out include allowing Pennsylvania to use the new federal Medicaid dollars to help adults who are eligible under the income guidelines to buy private health insurance on the online exchanges that open Jan. 1, the people familiar with the plan said.

Corbett also wants to require the enrollees to share the cost, for instance by paying a premium that is a percentage of their income, they said.

But first, Corbett will insist that the Obama administration approve changes to Pennsylvania’s existing Medicaid program for working-age adults, they said. For instance, he wants to require adults already on Medicaid — including pregnant women, parents and people with disabling conditions — to pay a premium and the able-bodied and unemployed among them to search for work.