The cost to replace all outdated equipment and infrastructure across the MBTA system with modern alternatives is about $2.8 billion more than the previous state-of-good-repair price estimate, officials said Monday.

In 2015, MBTA officials said addressing the entire maintenance backlog would cost about $7.3 billion, and they have cited that figure for years. But an assessment unveiled Monday, using new data about inventory and conditions collected over the past year, put the total modernization and replacement price tag at $10.1 billion.

The new figure is "fundamentally different," General Manager Steve Poftak said, because the data — which the MBTA had been required to collect following a Federal Transit Authority rule change — relied on different inventory counts and condition ratings than the past report.

Samantha Silverberg, the MBTA's senior director for capital planning, described the new estimate as a "fundamental reset" in how the authority thinks about its long-term needs, and MBTA officials during a briefing said that they do not believe the two estimates can be subjected to an "apples-to-apples" comparisons.

"This allows us to capture a much more realistic view of what the costs are to the MBTA to address capital needs in a real way and not in a much more imprecise like-for-like way, which was some of the thinking around 2015," Poftak said. "The current version is a much more accurate, precise and realistic assessment of the MBTA."

Officials based the new estimate on inventory data they gathered last year to submit to the FTA. Meeting the federal requirements helped produce a detailed list of every MBTA asset, and officials used that information and fresher cost estimates to project out all capital needs across the system.

The $10.1 billion figure is no longer just an estimate of what it will cost to bring the system into a state of good repair, but now refers to the cost of replacing or modernizing every currently outdated piece of equipment or infrastructure and also accounts for what Poftak described as "soft" expenses such as planning.

About $2.1 billion would be needed to replace more than 1,300 vehicles that have been in either passenger or non-passenger service beyond their useful lifespans. Repairs needed at stations, facilities and parking lots where conditions are insufficient make up nearly $4.8 billion of the total figure.

Despite the revised estimate of needs, officials said the MBTA is still on pace to bring the entire system to a state of good repair by 2032, the target date set by the Fiscal and Management Control Board. Silverberg and Poftak pointed to existing investments as important steps, saying the capital needs could have been significantly higher if not for about $3 billion in spending in recent years.

Officials also said the estimate does not include projects that are currently scheduled or underway. If every modernization project in the current five-year capital investment plan — including station reconstructions and purchase of new buses — is completed on time, the needs assessment would drop to about $6.1 billion, they said.

Using new metrics also showed some improvements, officials said. Almost three-quarters of all passenger vehicles rated as outside a state of good repair in the 2015 assessment, but only one in three are in need of replacement under the new definition used in the latest report.

The $10.1 billion total is a "point-in-time" estimate, Poftak said, and could change as placeholder assessments on commuter rail and station assets are finalized. But he believes the new framework will help MBTA officials better plan for how to meet the identified needs across the system, describing the challenges as "more apparent" but not "daunting."

"We know we are headed in the right direction, and we've got a plan to address the entire capital need," he said. "This just gives us more insight as to where the capital needs are and where we should prioritize the spending."

FMCB Chairman Joseph Aiello praised the new strategy during a Monday meeting, saying the clearer accounting of needs would help the MBTA reach "much more dependable, reliable footing."

Asked if the MBTA will need additional revenues to address the updated survey of needs, Poftak said the MBTA is fully funded through the draft five-year capital plan up to fiscal year 2024. Any future expansion projects, he said, would add complexity and warrant a long-term funding discussion.

The new estimate comes one week after Poftak unveiled a plan to spread out capital spending more gradually, a move that he said will delay some maintenance projects but would allow the MBTA enough time to hire 80 full-time new employees. With additional workers, the authority could have capacity needed to spend at least $1.5 billion per year on maintenance by fiscal year 2024 — a benchmark that Poftak said Monday is needed to fully address the entire slate of capital needs.

MBTA officials and Gov. Charlie Baker have said that their challenges stem more from staffing than from funding. In recent years, the authority was not able to spend as much as it had planned on reliability and modernization projects.