diff --git a/src/openapi/generation.jl b/src/openapi/generation.jl
index fcc62c2..defdd4d 100644
--- a/src/openapi/generation.jl
+++ b/src/openapi/generation.jl
@@ -292,6 +292,7 @@ function _make_hydro_dispatch_body!(
         "MW/min")
     set_value!(component, :base_power, mbase, "MVA")
     add_component!(sys, component)
+    set_component_ext!(sys, component, get(pm_gen, "ext", Dict{String, Any}()))
     return
 end
 
@@ -368,6 +369,7 @@ function make_renewable_dispatch!(
     set_value!(component, :power_factor, 1.0, "1")
     set_value!(component, :base_power, mbase, "MVA")
     add_component!(sys, component)
+    set_component_ext!(sys, component, get(pm_gen, "ext", Dict{String, Any}()))
     return
 end
 
@@ -402,6 +404,7 @@ function make_renewable_nondispatch!(
     set_value!(component, :power_factor, 1.0, "1")
     set_value!(component, :base_power, mbase, "MVA")
     add_component!(sys, component)
+    set_component_ext!(sys, component, get(pm_gen, "ext", Dict{String, Any}()))
     return
 end
 
@@ -485,11 +488,8 @@ function make_storage!(
     set_value!(component, :storage_technology_type, "OTHER_CHEM")
     set_value!(component, :storage_capacity, _natural_value(energy_rating, thermal_rating),
         "MWh")
-    set_value!(
-        component,
-        :storage_level_limits,
-        IC.MinMax(; min = 0.0, max = _natural_value(energy_rating, thermal_rating)),
-    )
+    # A fraction of storage_capacity; pm data carries no derate, so the full band.
+    set_value!(component, :storage_level_limits, IC.MinMax(; min = 0.0, max = 1.0))
     set_value!(component, :initial_storage_capacity_level, d["energy"] / energy_rating, "1")
     set_value!(component, :rating, _natural_value(thermal_rating, thermal_rating), "MVA")
     set_value!(component, :active_power, _natural_value(d["ps"], thermal_rating), "MW")
@@ -519,6 +519,7 @@ function make_storage!(
     )
     set_value!(component, :base_power, thermal_rating, "MVA")
     add_component!(sys, component)
+    set_component_ext!(sys, component, get(d, "ext", Dict{String, Any}()))
     return
 end
 
diff --git a/src/openapi/load.jl b/src/openapi/load.jl
index a419454..cdebde2 100644
--- a/src/openapi/load.jl
+++ b/src/openapi/load.jl
@@ -85,6 +85,7 @@ function _make_standard_load!(
     set_value!(load, :conformity, _conformity_string(Int(d["conformity"])))
     _set_zip_fields!(load, d, base_power)
     add_component!(sys, load)
+    set_component_ext!(sys, load, get(d, "ext", Dict{String, Any}()))
     return
 end
 
@@ -103,6 +104,7 @@ function _make_interruptible_standardload!(
     set_value!(load, :conformity, _conformity_string(Int(d["conformity"])))
     _set_zip_fields!(load, d, base_power)
     add_component!(sys, load)
+    set_component_ext!(sys, load, get(d, "ext", Dict{String, Any}()))
     return
 end
 
@@ -122,6 +124,7 @@ function _make_power_load!(
     set_value!(load, :max_reactive_power, d["qd"] * base_power, "MVAr")
     set_value!(load, :conformity, _conformity_string(Int(d["conformity"])))
     add_component!(sys, load)
+    set_component_ext!(sys, load, get(d, "ext", Dict{String, Any}()))
     return
 end
 
diff --git a/src/openapi/topology.jl b/src/openapi/topology.jl
index 8830675..9f743f9 100644
--- a/src/openapi/topology.jl
+++ b/src/openapi/topology.jl
@@ -211,6 +211,7 @@ function read_bus!(sys::OpenAPISystem, data::Dict; kwargs...)
             set_value!(bus, :bustype, "SLACK")
         end
         add_component!(sys, bus)
+        set_component_ext!(sys, bus, get(d, "ext", Dict{String, Any}()))
     end
     return
 end
diff --git a/test/test_openapi_generation.jl b/test/test_openapi_generation.jl
index c131775..d7d05cc 100644
--- a/test/test_openapi_generation.jl
+++ b/test/test_openapi_generation.jl
@@ -338,6 +338,9 @@ end
     @test PFP.get_value(storage, :reactive_power_limits).min ≈ -0.0075
     @test PFP.get_value(storage, :reactive_power_limits).max ≈ 0.0075
     @test PFP.get_value(storage, :initial_storage_capacity_level) == 0.5
+    # A fraction of storage_capacity: no derate means the full [0, 1] band.
+    @test PFP.get_value(storage, :storage_level_limits).min == 0.0
+    @test PFP.get_value(storage, :storage_level_limits).max == 1.0
     @test PFP.get_value(storage, :prime_mover_type) == "BA"
     @test PFP.get_value(storage, :storage_technology_type) == "OTHER_CHEM"
 end
@@ -386,6 +389,8 @@ end
     @test PFP.get_value(storage, :reactive_power_limits).max ≈ d["qmax"]
     # Dimensionless / ratio fields: untouched by COMPONENT_BASE either way.
     @test PFP.get_value(storage, :initial_storage_capacity_level) == 0.5
+    @test PFP.get_value(storage, :storage_level_limits).min == 0.0
+    @test PFP.get_value(storage, :storage_level_limits).max == 1.0
 end
 
 @testset "COMPONENT_BASE conversion errors loudly on an unregistered instance-dispatched field" begin
@@ -451,6 +456,41 @@ end
     @test PFP.get_value(hydro, :active_power) ≈ 500.0
 end
 
+@testset "hydro, renewable and storage makers carry their pm dict entry's ext" begin
+    sys = PFP.OpenAPISystem(100.0)
+    reg = PFP.get_registry(sys)
+    bus = _register_test_bus!(sys)
+    gen(type, name) = Dict{String, Any}(
+        "mbase" => 100.0, "gen_status" => true, "pg" => 5.0, "qg" => 1.0,
+        "pmax" => 20.0, "pmin" => 0.0, "qmax" => 10.0, "qmin" => -10.0,
+        "type" => type, "ext" => Dict{String, Any}("mRID" => name),
+    )
+    PFP.make_hydro_dispatch!(sys, reg, bus, gen("ROR", "hy1"), "hy1", 100.0)
+    PFP.make_hydro_reservoir!(sys, reg, bus, gen("HYDRO", "hy2"), "hy2", 100.0)
+    PFP.make_renewable_dispatch!(sys, reg, bus, gen("WIND", "wind1"), "wind1", 100.0)
+    PFP.make_renewable_nondispatch!(sys, reg, bus, gen("RTPV", "pv1"), "pv1", 100.0)
+    storage = Dict{String, Any}(
+        "energy_rating" => 50.0, "energy" => 25.0, "status" => true,
+        "thermal_rating" => 1.0, "ps" => 0.02, "charge_rating" => 0.05,
+        "discharge_rating" => 0.05, "charge_efficiency" => 0.9,
+        "discharge_efficiency" => 0.9, "qs" => 0.0, "qmin" => -0.05, "qmax" => 0.05,
+        "ext" => Dict{String, Any}("mRID" => "bat1"),
+    )
+    PFP.make_storage!(sys, reg, bus, storage, "bat1", 100.0)
+
+    components = vcat(
+        PFP.get_components(sys, "HydroDispatch"),
+        PFP.get_components(sys, "RenewableDispatch"),
+        PFP.get_components(sys, "RenewableNonDispatch"),
+        PFP.get_components(sys, "EnergyReservoirStorage"),
+    )
+    @test length(components) == 5
+    for component in components
+        @test PFP.get_ext(sys, PFP.get_value(component, :id)) ==
+              Dict{String, Any}("mRID" => PFP.get_value(component, :name))
+    end
+end
+
 @testset "get_generator_type resolving to EnergyReservoirStorage from \"gen\" is an error, not a skip" begin
     sys = PFP.OpenAPISystem(100.0)
     reg = PFP.get_registry(sys)
diff --git a/test/test_openapi_load.jl b/test/test_openapi_load.jl
index b88919c..0a534e7 100644
--- a/test/test_openapi_load.jl
+++ b/test/test_openapi_load.jl
@@ -143,3 +143,43 @@ end
         @test PFP.get_value(load, :conformity) == "CONFORMING"
     end
 end
+
+@testset "every load type carries its pm dict entry's ext" begin
+    pm = fourteen_bus_pm_data()
+    data = deepcopy(pm.data)
+    data["load"][first(keys(data["load"]))]["interruptible"] = 1
+    for (key, d) in data["load"]
+        d["ext"]["mRID"] = "load-$key"
+    end
+    sys = PFP.OpenAPISystem(Float64(data["baseMVA"]))
+    PFP.read_loadzones!(sys, data)
+    PFP.read_bus!(sys, data)
+    PFP.read_loads!(sys, data)
+    loads = vcat(
+        PFP.get_components(sys, "StandardLoad"),
+        PFP.get_components(sys, "InterruptibleStandardLoad"),
+    )
+    @test length(loads) == 13
+    for load in loads
+        d = only(
+            v for v in values(data["load"]) if
+            strip(join(v["source_id"])) == PFP.get_value(load, :name)
+        )
+        @test PFP.get_ext(sys, PFP.get_value(load, :id)) == d["ext"]
+    end
+
+    pm = PFP.PowerModelsData(joinpath(MATPOWER_DIR, "case5.m"))
+    for (key, d) in pm.data["load"]
+        d["ext"] = Dict{String, Any}("mRID" => "load-$key")
+    end
+    sys = PFP.build_openapi_system(pm)
+    loads = PFP.get_components(sys, "PowerLoad")
+    @test length(loads) == 3
+    for load in loads
+        d = only(
+            v for v in values(pm.data["load"]) if
+            strip(join(v["source_id"])) == PFP.get_value(load, :name)
+        )
+        @test PFP.get_ext(sys, PFP.get_value(load, :id)) == d["ext"]
+    end
+end
diff --git a/test/test_openapi_topology.jl b/test/test_openapi_topology.jl
index 29cfc7c..d669242 100644
--- a/test/test_openapi_topology.jl
+++ b/test/test_openapi_topology.jl
@@ -158,6 +158,18 @@ end
     @test all(b -> PFP.get_value(b, :bustype) != "SLACK", other)
 end
 
+@testset "ACBus carries its pm dict entry's ext" begin
+    pm = fourteen_bus_pm_data()
+    for (number, d) in pm.data["bus"]
+        d["ext"] = Dict{String, Any}("mRID" => "bus-$number")
+    end
+    sys = PFP.build_openapi_system(pm)
+    for bus in PFP.get_components(sys, "ACBus")
+        ext = PFP.get_ext(sys, PFP.get_value(bus, :id))
+        @test ext == Dict{String, Any}("mRID" => "bus-$(PFP.get_value(bus, :number))")
+    end
+end
+
 @testset "Area.ext carries PSS/E AREA DATA metadata matched by area_number" begin
     pm_data =
         PFP.PowerModelsData(joinpath(@__DIR__, "fixtures", "v35_area_slack_variants.raw"))