If you build or retrofit California hospitals, the Non-Structural Performance Category — NPC — is the single number that tells you how much anchorage and bracing the job really carries. Assigned by HCAI (the Department of Health Care Access and Information, formerly OSHPD) to every general acute care hospital building, the NPC rating drives the scope for everything that is not the building frame: equipment, piping, ductwork, conduit, medical gas, fire protection, ceilings, and on-site utilities. This guide explains what each rating means in practical terms, what the law requires and by when, and what an NPC scope looks like when it lands on your desk as stamped submittals.

NPC in one paragraph

California's hospital seismic program assigns two ratings to every general acute care building. SPC (Structural Performance Category) rates the building's structure — beams, columns, shear walls, foundations. NPC rates the anchorage and bracing of the nonstructural systems inside it. A hospital can only remain in acute care service past January 1, 2030 if its buildings are both SPC and NPC compliant — and the only 2030-compliant NPC rating is NPC 5. For the full building-classification picture (OSHPD 1 vs 2 vs 3, SPC-4D, and how the ratings interact), see our HCAI building classifications guide.

The NPC ladder, NPC 1 through NPC 5

Each step up the ladder adds systems that must be braced or anchored. In practical terms for a contractor:

  • NPC 1 — minimal bracing of nonstructural systems. Equipment and distribution systems were largely installed without engineered seismic restraint.
  • NPC 2 — bracing of communications, emergency power, and select essential systems. This is where generators, ATSs, and emergency electrical distribution first enter the anchorage scope.
  • NPC 3 — adds bracing of critical piping, medical gas, and fire protection systems. Retrofit work at this level touches occupied patient-care areas, which drives phasing and infection control requirements.
  • NPC 4 — adds on-site water storage and holding capacity for fire suppression and domestic use, plus broader equipment anchorage. Water tanks, pumps, and their foundations become part of the seismic scope.
  • NPC 5 — full nonstructural compliance: the building's nonstructural systems are expected to remain functional so the hospital can continue providing services after a strong earthquake. This is the rating every acute care building needs by 2030.

There is also an NPC 4D evaluation path — analogous to the structural SPC-4D methodology — that some facilities use as an interim step. The end state is the same: NPC 5.

Deadlines and extensions a contractor should know

The statutory deadline is January 1, 2030: after that date, a building rated below NPC 5 generally cannot be used for general acute care services. Two pieces of legislation shape the real schedule:

  • AB 1882 — requires hospitals to report their seismic compliance status annually, with public postings and notices. For contractors, this means the compliance clock and the facility's status are public information, and owners are under visible pressure to show progress.
  • AB 869 (effective January 1, 2025, implemented by HCAI PIN 80) — allows HCAI to grant a delay of up to three years beyond 2030, and up to an additional two years — a maximum of January 1, 2035 — for hospitals facing financial distress or documented contractor, labor, or material delays and other circumstances beyond the hospital's control. Eligible hospitals had to submit their NPC 4, 4D, and 5 evaluations by January 1, 2025, and a compliance plan by January 1, 2026.

Practical takeaway: an AB 869 extension delays the deadline, not the scope. The work to reach NPC 5 is the same work — it just lands on a longer schedule. Buildings still must obtain permits for their NPC 4/4D/5 construction projects.

What an NPC scope means for anchorage and bracing

Raising an NPC rating is, at its core, an anchorage and bracing program. On a typical NPC retrofit or upgrade project, the nonstructural scope breaks down like this:

  • Mechanical and electrical equipment — chillers, air handlers, generators, switchgear, transformers, UPSs, and pumps anchored to structure with engineered anchorage designed to the nonstructural component provisions of ASCE 7 (Chapter 13 in ASCE 7-22) and, where anchors connect to concrete, designed and justified per ACI 318 Chapter 17. Active equipment that must function after the earthquake — designated seismic systems — additionally needs special seismic certification, typically by shake-table testing per ICC-ES AC156 or by an HCAI preapproval.
  • Distribution systems — piping, ductwork, and conduit braced per the ASCE 7 distribution-system provisions, with bracing layouts, attachment details, and flexible connections engineered and shown on submittal drawings.
  • Medical gas and fire protection — the NPC 3 additions. Medical gas piping is life-safety critical and tightly reviewed; fire sprinkler bracing follows NFPA 13 seismic provisions.
  • On-site water (NPC 4) — storage tanks, holding systems, and their anchorage, plus the supporting civil and structural work.

The submittals behind the scope

Every line of NPC anchorage scope is backed by paper. On HCAI-jurisdiction work you should expect to see — or be asked to produce:

  • Stamped anchorage calculations signed by a California-licensed engineer: demand per ASCE 7-22 Chapter 13 (Fp, including the height-amplification and overstrength factors), anchor capacity per ACI 318-19 Chapter 17, and the supporting drawings. Our stamped calculation package guide walks through what a complete package contains.
  • Preapproval references where they apply: HCAI OSP (Special Seismic Certification Preapproval) for the equipment itself, PCS for preapproved component systems, and OPM for preapproved anchorage or bracing designs. Using a valid preapproval can take entire packages of project-specific engineering off the critical path — check the OSP database early.
  • Equipment classification per HCAI PIN 68 — fixed, mobile, and movable equipment are treated differently, and the classification decides what anchorage documentation each item needs. See our PIN 68 guide.

Scope traps that catch contractors on NPC work

  • Existing concrete. NPC retrofits anchor into existing slabs and walls of unknown quality. Rebar scanning, reduced edge distances, and lower-strength concrete routinely force anchor redesigns after award. Carry scanning and redesign allowances.
  • Survey surprises. Ratings are assigned from evaluations, but field verification finds unbraced runs, undocumented equipment swaps, and improvised supports that were never in the evaluation. Existing-condition verification belongs in the preconstruction budget.
  • Occupied-hospital phasing. NPC 3-level work in patient-care areas means infection control, shutdown windows, and ICRA/ILSM coordination that can dominate the schedule more than the anchorage work itself.
  • Certification mismatches. An OSP covers a specific equipment configuration; a substituted unit, a swapped vibration isolator, or a changed mounting can invalidate it. Confirm preapproval coverage against the exact bill of material before procurement.

A contractor's NPC checklist

  1. Pull the building's current SPC/NPC ratings from HCAI's published ratings (updated every two weeks) before bidding.
  2. Confirm the facility's compliance plan status and any AB 869 extension — it changes schedule, not scope.
  3. Identify which equipment carries OSP/PCS/OPM preapprovals and verify the covered configurations match the specified units.
  4. Budget existing-concrete scanning and anchor redesign contingencies for retrofit anchorage.
  5. Line up the anchorage engineering early — stamped calculations and HCAI plan-check review lead times belong on the procurement schedule, not after equipment is on site.

Need the engineering side of an NPC scope — anchorage design, stamped calculations, or certification strategy? See our hospital equipment anchorage services and HCAI seismic certification pages, or contact our engineering team about your project.

This article is an informational overview, not engineering or legal advice. NPC requirements are assigned and enforced by HCAI per the Alfred E. Alquist Hospital Facilities Seismic Safety Act, the California Building Standards Code (Title 24), and current HCAI policy; confirm project-specific obligations with HCAI and the project's engineer of record.