What's the biggest rebate stack on a heat pump conversion?

In Massachusetts and a few northeast states with aggressive utility programs, an oil-to-heat-pump conversion can stack up to ~$12,000 in 2026: $8,000 HEEHRA (income-qualified) plus $3,000–$4,000 from Mass Save / Eversource / National Grid utility rebates. (The $2,000 federal 25C credit that used to stack on top expired Dec 31, 2025.) Even non-income-qualified households typically see $3,000–$4,000 from utility rebates alone. The highest 2026 incentive concentration is in MA, CT, RI, ME, and NH — driven by aggressive state climate goals + tight winter electricity capacity that utilities want to shift away from oil/gas heat.